Stock market: Here's what usually happens after a 20% plunge Yahoo Finance, 7/10/22
https://www.msn.com/en-us/money/markets/stock-market-here-s-what-usually-happens-after-a-20-plunge/ar-AAZqi0r

Going all the way back to 1950 according to the table --

I'm going by the table, which differs from the article's narrative a bit.

There are 10 cases total of a 20% or more drop from a record high since 1950. The 10th case is the March 2020 bear market, and we don't have 3 years later results yet

After 1 year: 7 out of 10 were positive, with an average return of +15%.

After 2 years: 7 out of 10 were positive with an average return of +26%

After 3 years: 8 out of 9 were positive with an average return of +29%

The average return includes the ones with negative returns, e.g. for the "after 2 years" case:
(46 + 45 + 36 + 20 - 6 + 40 + 48 - 27 - 17 + 72)/10 = +25.7