The interactive chart helps you:
The chart shows the numbers of mailings sent within a month, opens (% of sent) and the click-throughs (% of opened). The x axis shows the months. Number of mailings is listed on the right-side y axis, while open and click percentages are listed on the left-side y axis.
The chart on the main Response page allows you to:
Don't see the interactive chart? This graph will not show if your account has fewer than two months of history. You'll also need to make sure that you have Flash installed; without Flash, you'll see the chart's title but not the chart itself.