The gist of the story goes as follow:

1. The most popular languages are JavaScript/TypeScript and Python with roughly 20% of all pull requests each. In effect, if you put JavaScript/TypeScript and Python together, you get about 40% of all pull requests.
2. Then you get the second tier languages: Java and Scala, C/C++, and Go. They all are in the 10% to 15% range.
3. Finally, you have PHP, Ruby and C# that all manage to get about 5% of all pull requests.
4. Other languages are typically far below 5%.