Damn, I would really love for us to get 40 countries
Countries that haven't re-registered into the 2020 edition: Chile, Morocco, Slovakia, Sweden
Countries that we've been missing since 2019 contests: Canada, Egypt, Finland, Great Britain, Kazakhstan, Moldova, Bulgaria, Colombia, Germany, Russia, Turkey, Venezuela
Countries that we've been missing since 2018 contests: Austria, Azerbaijan, Estonia, Iran, Switzerland (these five probably hurt the most for me personally, because of the amount of times they got points from me, Austria and Switzerland getting 12s)
Countries that we've been missing since 2017 contests: Czech Republic
And from earlier years I recall Latvia, Montenegro, Vietnam, Guyana, Lebanon.
That's like 27 countries, some of those are still fairly frequent users, so it shouldn't be impossible.