I'm new to using the Issue Count Burndown Chart in Jira, and would like some help in understanding why the initial count of tickets changes? For example if I am tracking the sprint and would like to know the initial amount of tickets placed in sprint so I was looking at the burndown chart day 1 when the sprint opened. For example it says 60 tickets, but as the sprint progresses that original day count changes. Assuming there is an easy answer, but I'm not sure! Can someone help?