The count is a reflection of your time period. You are reporting a week's worth of data (7 days). That's divided into a number of periods. I see approximately 10 points in your graph between days. Based on that, each data point is representative of about 8,640 seconds (about 2.5 hours).
It's saying we collected a CPU measurement 3900 times in that interval, then averaged those values to provide the average CPU utilization of 24% during the 2.5 hours represented by the data point. If you look at just that 2.5 hours of data, you'll see different averages and counts throughout the period.