There are benchmarks on https://arewefastyet.com https://arewefastyet.com. Sadly they do not go as far back in time as they used to; the absolute speed increase

There are benchmarks on https://arewefastyet.com https://arewefastyet.com. Sadly they do not go as far back in time as they used to; the absolute speed increase that Firefox has had over its lifetime is quite impressive. They’ve made progress in virtually every release since version 4.0.