Cache do save a copy of dynamic contents to serve them instantly.
I've spidered the whole website and collected the TTFB for every page (x axis correspond to each page), the y axis reports the TTFB for that page in seconds. You can observe a strong difference between pages which were cached and pages which were rendered on the fly.
For my purpose you can consider the y axis only. I'd like to get a distribution of probability that can be easily summarized and compared with the result of a new test.
I've put the mydata here: https://www.wolframcloud.com/obj/7430bbee-8954-4a4e-b0a6-ee9fdb69c2f4
mydata2 = Rest[mydata][[All, 2]];