You can see where it compares infections to proportion of strain that they only spiked when "L" disappeared and one or more of the "G" ones became dominant. There's only 7 countries listed here, but I think I remember a different article that had more, and the pattern was pretty consistent.
This is from late last year, an article that attempted to group the mutations into "L", "G", "S", "O", etc, strains: https://graphics.reuters.com/HEALTH-CORONAVIRUS/EVOLUTION/yx...
You can see where it compares infections to proportion of strain that they only spiked when "L" disappeared and one or more of the "G" ones became dominant. There's only 7 countries listed here, but I think I remember a different article that had more, and the pattern was pretty consistent.