The Status Change report tracks the movement of both Leads and Opportunities from Status to Status through your sales funnel. It gives you the number of Leads in each previous status and shows where those Leads went in a given time period. With the data given, you can also calculate (outside of Close) what the conversion percentage is for each of your Statuses.
To see more detail, you can click on any number to see the related search results. You can also click the arrow under next to each status to expand the report into a graph that shows more detailed numbers on the movement of each Lead or Opportunity Status.
In the example above, we can see that 597 Leads entered into the Status of Potential this year. When I click to expand the report, I can see all the individual Leads that moved into the Potential Status and then moved out of the Potential Status. If I wanted to understand the conversion rate from Potential to Qualified, I can see quickly that 811 Leads moved to the Qualified Status. I can also click on number 811 to see the exact Leads that match that Search.