At the top of the section the three reports are a snapshot of your account since it was created.
Total number of supporters shows the total amount of supporters since your account was created, unsubscribed or subscribed. 30 Day Change and 90 Day Change will give you a quick look at the total changes in that amount of time.
Total number of subscribers shows the total amount of supporters who are subscribed (can receive your emails) since your account was created. 30 Day Change and 90 Day Change will give you a quick look at the total changes in that amount of time.
Total Donors will show the amount of supporters who have donated. 30 Day Change and 90 Day Change will give you a quick look at the total changes in that amount of time.
In the lower section you will see several graphs. The 30d, 90d, 1y and ALL buttons will automatically filter the information included in the graphs by those timeframes.
If you have a specific date range you want to filter by click the date dropdown and select the range of days and click Apply.
The New Supporters report will show you how many new supporters were added to your account in the time range specified. It will also let you know how many of those supporters were subscribers (they can receive your emails) and how many were new donors.
The Supporter Actions report will show you how many actions have occurred on your account in the time range specified. Actions are signups (from a signup form) and donations (from a donation form) and petition signatures (from a Petition form).
The last report is a Summary report that gives a snapshot of different actions that can occur on your account.
If you want to change what you see in this report click the Filter Results dropdown and choose which data points you want to see.