Was just looking at this chart: https://bitinfocharts.com/comparison/ethereum-hashrate.html

The mining boom started around spring 2017.

Spring 2017 - Summer 2017: ~40T increase
Summer 2017 - Autumn 2017: ~40T increase
Autumn 2017 - Winter 2018: ~60T increase
Winter 2018 - Spring 2018: ~110T increase

Oook. IMO the height of the average joe mining boom was around late summer 2017, that's when the hardware was most expensive, mining most profitable and that's when I'd expect the biggest increase.

However the increase since winter 2018 has been more than double of that. That just seems unlikely based on mining profitability and also it would have required GPU manufacturers to double their production.

I'm 98% convinced ASIC manufacturers started bringing first ETH asics online at around december 2017 and have been steadily building and mining with them ever since.