EDIT: I stand corrected based on github code files (which might better represent application CRUD queries versus use by analysts, more thought required!)
SELECT: 7.3M code results [0]
INSERT: 8.9M code results [1]
UPDATE: 5.5M code results [2]
DELETE: 5.0M code results [3]
[0] https://github.com/search?q=select++extension%3Asql&type=Cod...
[1] https://github.com/search?q=insert++extension%3Asql&type=Cod...
[2] https://github.com/search?q=update++extension%3Asql&type=Cod...
[3] https://github.com/search?q=delete++extension%3Asql&type=Cod...