diff --git a/README.md b/README.md
index e31bddb..419f268 100644
--- a/README.md
+++ b/README.md
@@ -98,3 +98,8 @@ Also, `index.html` must be modified to include these lines:
     <script type="text/javascript" src="react-dom.production.min.js"></script>
     <script type="text/javascript" src="react-redux.min.js"></script>
 ```
+
+
+If you need to make changes to the `fps-emit` package, bump the version number in its `package.json`,
+then update each benchmark to use the newest version using `yarn upgrade-interactive` and selecting `fps-emit`
+for an update.  Then rebuild all the benchmarks using `yarn initialize`
diff --git a/fps-emit/package.json b/fps-emit/package.json
index 344b3c6..44d0046 100644
--- a/fps-emit/package.json
+++ b/fps-emit/package.json
@@ -1,11 +1,14 @@
 {
   "name": "fps-emit",
   "private": true,
-  "version": "1.0.0",
+  "version": "1.0.1",
   "description": "fps emitter",
   "main": "src/index.js",
   "scripts": {
-    "build": "cross-env BABEL_ENV=rollup NODE_ENV=production rollup -c -o dist/fps-emit.min.js",
+    "build:commonjs": "cross-env BABEL_ENV=commonjs babel src --out-dir lib",
+    "build:es": "babel src --out-dir es",
+    "build:umd:min": "cross-env NODE_ENV=production rollup -c -o dist/react-redux.min.js",
+    "build": "yarn run build:commonjs && yarn run build:es && yarn run build:umd:min",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "author": "Gregory Beaver <greg.beaver.cello@gmail.com>",
diff --git a/fps-emit/src/index.js b/fps-emit/src/index.js
index 03652d0..d64a9b9 100644
--- a/fps-emit/src/index.js
+++ b/fps-emit/src/index.js
@@ -13,6 +13,12 @@ fps.on("update", function(FPS) {
 });
 
 const getFpsStats = () => {
+  // fake a final entry with the same FPS
+  const finalFPS = fps.__fps
+  marker.mark("FPS", {
+      details: { FPS : finalFPS, isFinal : true }
+  });
+
   const logData = performance.getEntriesByType("mark").map(entry => {
     const meta = marker.getEntryMetadata(entry);
     return {
diff --git a/runBenchmarks.js b/runBenchmarks.js
index 412c4c9..b5f611d 100644
--- a/runBenchmarks.js
+++ b/runBenchmarks.js
@@ -83,32 +83,29 @@ async function runBenchmarks() {
 
         const averageFPS = fpsValuesWithoutFirst.reduce((sum, entry) => sum + entry.FPS, 0) / fpsValuesWithoutFirst.length || 0;
 
-        const fpsValuesPlusFakeEntries = [
-            ...fpsValuesWithoutFirst,
-            {...lastEntry, timestamp : length * 1000}
-        ]
-
-        const pairwiseEntries = pairwise(fpsValuesPlusFakeEntries);
+        const pairwiseEntries = pairwise(fpsValuesWithoutFirst);
 
         const fpsValuesWithDurations = pairwiseEntries.map(pair => {
           const [first, second] = pair;
           const duration = second.timestamp - first.timestamp;
+          const durationSeconds = duration / 1000.0
 
-          return {FPS : second.FPS, duration}
+          return {FPS : first.FPS, durationSeconds}
         })
 
         const sums = fpsValuesWithDurations.reduce( (prev, current) => {
+          const weightedFPS = current.FPS * current.durationSeconds;
+
           return {
-            FPS : prev.FPS + current.FPS,
-            duration : prev.duration + current.duration
+            weightedFPS : prev.weightedFPS + weightedFPS,
+            durationSeconds : prev.durationSeconds + current.durationSeconds,
           }
-        }, {FPS : 0, duration : 0});
+        }, {FPS : 0, weightedFPS : 0, durationSeconds : 0});
 
-        const durationSeconds = sums.duration / 1000.0;
 
-        const weightedFPS = sums.FPS / durationSeconds;
+        const weightedFPS = sums.weightedFPS / sums.durationSeconds;
 
-        const fps = {averageFPS, weightedFPS, values : fpsValues}
+        const fps = {averageFPS, weightedFPS, values : fpsValuesWithoutFirst}
 
         versionPerfEntries[version] = {fps, profile : {categories}};
 
diff --git a/utils/server.js b/utils/server.js
index f446166..e77ff00 100644
--- a/utils/server.js
+++ b/utils/server.js
@@ -64,8 +64,8 @@ module.exports = {
     ) || []
 
     fpsValues = fpsStatsEntries.map(entry => {
-      const {FPS} = entry.meta.details;
-      return {FPS, timestamp : entry.timeStamp};
+      const {FPS, isFinal} = entry.meta.details;
+      return {FPS, timestamp : entry.timeStamp, isFinal};
     });
 
     await page.close();