"No less than" is idiomatic [1]. It means "impressive number". People don't use "no fewer than". [1] https://www.merriam-webster.com/dictionary/no%20less%20tha

"No less than" is idiomatic [1]. It means "impressive number". People don't use "no fewer than". [1] https://www.merriam-webster.com/dictionary/no%20less%20than https://www.merriam-webster.com/dictionary/no%20less%20than