There have been 865 total 737 reports in the ASRS database since 1/1/2018 (linked the results of my search in another comment in this thread). There doesn't appear to be a 737-MAX filter (groups all 737-800s and 737-900s together it seems), so it's tough to say.
In addition, it seems like some pilots were motivated to submit reports on their MAX experiences due to the Lion Air incident.