diff --git a/analyses/pluginLEP/OPAL_1997_S3396100.cc b/analyses/pluginLEP/OPAL_1997_S3396100.cc
--- a/analyses/pluginLEP/OPAL_1997_S3396100.cc
+++ b/analyses/pluginLEP/OPAL_1997_S3396100.cc
@@ -1,163 +1,145 @@
 // -*- C++ -*-
 #include "Rivet/Analysis.hh"
 #include "Rivet/Projections/Beam.hh"
 #include "Rivet/Projections/FinalState.hh"
 #include "Rivet/Projections/ChargedFinalState.hh"
 #include "Rivet/Projections/UnstableParticles.hh"
 
 namespace Rivet {
 
 
   /// @brief OPAL strange baryon paper
   /// @author Peter Richardson
   class OPAL_1997_S3396100 : public Analysis {
   public:
 
     /// Constructor
     OPAL_1997_S3396100()
-      : Analysis("OPAL_1997_S3396100"),
-        _weightedTotalNumLambda(0.)     ,_weightedTotalNumXiMinus(0.),
-        _weightedTotalNumSigma1385Plus(0.),_weightedTotalNumSigma1385Minus(0.),
-        _weightedTotalNumXi1530(0.)   ,_weightedTotalNumLambda1520(0.)
+      : Analysis("OPAL_1997_S3396100")
     {}
 
 
     /// @name Analysis methods
     //@{
 
     void init() {
       declare(Beam(), "Beams");
       declare(ChargedFinalState(), "FS");
       declare(UnstableParticles(), "UFS");
       _histXpLambda         = bookHisto1D( 1, 1, 1);
       _histXiLambda         = bookHisto1D( 2, 1, 1);
       _histXpXiMinus        = bookHisto1D( 3, 1, 1);
       _histXiXiMinus        = bookHisto1D( 4, 1, 1);
       _histXpSigma1385Plus  = bookHisto1D( 5, 1, 1);
       _histXiSigma1385Plus  = bookHisto1D( 6, 1, 1);
       _histXpSigma1385Minus = bookHisto1D( 7, 1, 1);
       _histXiSigma1385Minus = bookHisto1D( 8, 1, 1);
       _histXpXi1530         = bookHisto1D( 9, 1, 1);
       _histXiXi1530         = bookHisto1D(10, 1, 1);
       _histXpLambda1520     = bookHisto1D(11, 1, 1);
       _histXiLambda1520     = bookHisto1D(12, 1, 1);
     }
 
 
     void analyze(const Event& e) {
       // First, veto on leptonic events by requiring at least 4 charged FS particles
       const FinalState& fs = apply<FinalState>(e, "FS");
       const size_t numParticles = fs.particles().size();
 
       // Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
       if (numParticles < 2) {
         MSG_DEBUG("Failed leptonic event cut");
         vetoEvent;
       }
       MSG_DEBUG("Passed leptonic event cut");
 
       // Get event weight for histo filling
       const double weight = e.weight();
 
       // Get beams and average beam momentum
       const ParticlePair& beams = apply<Beam>(e, "Beams").beams();
       const double meanBeamMom = ( beams.first.p3().mod() +
                                    beams.second.p3().mod() ) / 2.0;
       MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
 
       // Final state of unstable particles to get particle spectra
       const UnstableParticles& ufs = apply<UnstableFinalState>(e, "UFS");
 
       foreach (const Particle& p, ufs.particles()) {
         const int id = p.abspid();
         double xp = p.p3().mod()/meanBeamMom;
         double xi = -log(xp);
         switch (id) {
         case 3312:
           _histXpXiMinus->fill(xp, weight);
           _histXiXiMinus->fill(xi, weight);
-          _weightedTotalNumXiMinus += weight;
           break;
         case 3224:
           _histXpSigma1385Plus->fill(xp, weight);
           _histXiSigma1385Plus->fill(xi, weight);
-          _weightedTotalNumSigma1385Plus += weight;
           break;
         case 3114:
           _histXpSigma1385Minus->fill(xp, weight);
           _histXiSigma1385Minus->fill(xi, weight);
-          _weightedTotalNumSigma1385Minus += weight;
           break;
         case 3122:
           _histXpLambda->fill(xp, weight);
           _histXiLambda->fill(xi, weight);
-          _weightedTotalNumLambda += weight;
           break;
         case 3324:
           _histXpXi1530->fill(xp, weight);
           _histXiXi1530->fill(xi, weight);
-          _weightedTotalNumXi1530 += weight;
           break;
         case 3124:
           _histXpLambda1520->fill(xp, weight);
           _histXiLambda1520->fill(xi, weight);
-          _weightedTotalNumLambda1520 += weight;
           break;
         }
       }
     }
 
 
     /// Finalize
     void finalize() {
-      normalize(_histXpLambda        , _weightedTotalNumLambda       /sumOfWeights());
-      normalize(_histXiLambda        , _weightedTotalNumLambda       /sumOfWeights());
-      normalize(_histXpXiMinus       , _weightedTotalNumXiMinus      /sumOfWeights());
-      normalize(_histXiXiMinus       , _weightedTotalNumXiMinus      /sumOfWeights());
-      normalize(_histXpSigma1385Plus , _weightedTotalNumSigma1385Plus/sumOfWeights());
-      normalize(_histXiSigma1385Plus , _weightedTotalNumSigma1385Plus/sumOfWeights());
-      normalize(_histXpSigma1385Minus, _weightedTotalNumSigma1385Plus/sumOfWeights());
-      normalize(_histXiSigma1385Minus, _weightedTotalNumSigma1385Plus/sumOfWeights());
-      normalize(_histXpXi1530        , _weightedTotalNumXi1530       /sumOfWeights());
-      normalize(_histXiXi1530        , _weightedTotalNumXi1530       /sumOfWeights());
-      normalize(_histXpLambda1520    , _weightedTotalNumLambda1520   /sumOfWeights());
-      normalize(_histXiLambda1520    , _weightedTotalNumLambda1520   /sumOfWeights());
+      double fact=1./sumOfWeights();
+      scale(_histXpLambda        , fact);
+      scale(_histXiLambda        , fact);
+      scale(_histXpXiMinus       , fact);
+      scale(_histXiXiMinus       , fact);
+      scale(_histXpSigma1385Plus , fact);
+      scale(_histXiSigma1385Plus , fact);
+      scale(_histXpSigma1385Minus, fact);
+      scale(_histXiSigma1385Minus, fact);
+      scale(_histXpXi1530        , fact);
+      scale(_histXiXi1530        , fact);
+      scale(_histXpLambda1520    , fact);
+      scale(_histXiLambda1520    , fact);
     }
 
     //@}
 
 
   private:
 
-    /// Store the weighted sums of numbers of charged / charged+neutral
-    /// particles - used to calculate average number of particles for the
-    /// inclusive single particle distributions' normalisations.
-    double _weightedTotalNumLambda;
-    double _weightedTotalNumXiMinus;
-    double _weightedTotalNumSigma1385Plus;
-    double _weightedTotalNumSigma1385Minus;
-    double _weightedTotalNumXi1530;
-    double _weightedTotalNumLambda1520;
-
     Histo1DPtr _histXpLambda        ;
     Histo1DPtr _histXiLambda        ;
     Histo1DPtr _histXpXiMinus       ;
     Histo1DPtr _histXiXiMinus       ;
     Histo1DPtr _histXpSigma1385Plus ;
     Histo1DPtr _histXiSigma1385Plus ;
     Histo1DPtr _histXpSigma1385Minus;
     Histo1DPtr _histXiSigma1385Minus;
     Histo1DPtr _histXpXi1530        ;
     Histo1DPtr _histXiXi1530        ;
     Histo1DPtr _histXpLambda1520    ;
     Histo1DPtr _histXiLambda1520    ;
     //@}
 
   };
 
 
 
   // The hook for the plugin system
   DECLARE_RIVET_PLUGIN(OPAL_1997_S3396100);
 
 }