What does "X-Request-Count" means in BitBucket API response header?

I saw there is a header name X-Request-Count in BitBucket API response header. What does it mean?

Does it mean I’ve made X requests in total? Based on what period? Per day? Per month? Lifetime?

Does it mean I have X left in the rate limit balance pool?

I’m trying to find a way to see how much left in my BitBucket rate limit balance pool. Something like this. Is there any?