How often do they release Topps players?

Just need to do this for the trout collection. Wondering how often do they release new cards?

At the start of last year, they'd release them in one bunch along with the POTMs.

Sometime mid year, they started doing Weekly Moments where if you did all of the Moments dropped for a particular week, you'd get a bonus Topps Now card. Additional cards continued to be released with the POTMs.