1 base for multiple years vs. individual base per year

What do people here prefer? I know there’s been requests and talk about linking bases but obviously that’s not an option at this point.

I use Airtable for tracking processes, employee info, and data for our events. We have between 450-500 records (events) per year. 2018 was the first year I used Airtable so when 2019 rolled around I made a new base for the year. At that point, the base structure/construction was pretty much flushed out, and my 2018 base looks more like an experiment in hindsight. 2020 seems to be right around the corner and we are currently debating whether or not to continue using our 2019 base, adding in the 2020 events, and filtering out the previous year; or copying the base structure/construction, and clearing out the 2019 data.