Sounds way too little imo. With "inofficial" zaps probably 5x more minimum.
Discussion
For example, I have the PROD version of Damus on my phone. No zapping there. Just normal lightning transactions from me that are a quasi-zap.
Official zaps are growing fast, but yeah, if all the non-Zap LN payments were calculated it's a lot more (just based on my own receiving of LN+Zaps).