Market Intel (Event Listings) API now returns the number of events you've used in the current calendar month. You'll find this response header in each API response: X-SH-Events-Limit-Used. The number of events counter resets at the beginning of the next calendar month.
For example, if you subscribed to a 1000 events/month Market Intel rate plan, and X-SH-Events-Limit-Used is 750, it indicates that you can fetch data for 250 new events in the current calendar month.