gzip vs Brotli compression

I enabled Brotli on one of the sites that I run (https://docs.trafficserver.apache.org/ and https://ci.trafficserver.apache.org). I examined the logs (about 200,000 log entries so far), and comparing the sizes for each URL that gets both Brotli and gzip. I summarized by content type, and see 5-10% smaller objects with Brotli.

application/javascript  -6.42%
text/css               -10.05%
text/plain              -4.64%
text/html               -8.44%