Thebusinessofdomains.com

According to Verisign in 2019 here are the stats:

1. .com – 144 million
2. .tk – 25.1 million
3. .cn – 23 million
4. .de – 16.3 million
5. .net – 13.4 million
6. .uk – 13.3 million
7. .org – 10 million
8. .tw – 6.8 million
9. .nl – 5.9 million
10. .ru – 5.7 million