I see that you're using a constant in `buffer/buffer-base64-encode.js`. Right now my score is `10.5`, otherwise calculated `64 / 10.4 ≈ 6.15 sec`. So say over three releases we're able to reduce the run time of the benchmark by `1 sec` per release. A nice linear trend. Though with the current scoring method it would show as `12.43`, `15.42` and `20.32` respectively.

So here the issue is two fold. First the `dx` is inverted, `fn(20.32, 10.5) ≈ 95.5%` vs `fn(3.15, 5.15) ≈ -38.8%`. Second the graph would misrepresent the actual performance gains if graphed over time. This is on reason why the v8 benchmarks are so skewed, and are nice for show but not so much for measuring proper performance (says the team of PhD statisticians I've been working with over the last year while creating performance dashboards).