For example, here’s one that can work for ''improve%" – you can modify taxon, location, or several other parameters:
https://www.inaturalist.org/observations/identify?created_d1=1700-01-01&created_d2=2020-09-30&createdDateType=range&place_id=any
You can customize it yourself or I’ll make one for you if you’re not sure how. Check out How to use iNaturalist’s Search URLs - wiki for tips.
I’ll be giving exact parameters for each category, so that it’s transparent what will be counted and what is not, closer to the event.