I didn't recognise hardly any of the frameworks in that list so here's my little translation of the top 6 for people like me:

1: Drogon (c++ Framework)

2: Actix (Rust Framework)

3: may-minihttp (Rust Framework)

4: Lithium (C++ Framework)

5: Jooby.x (Java/Kotlin Framework)

6: asp.net core

So I guess that would be .NET Core 3.1