Whenever you use the PostureTracker, it will track the time you use it for, and the exercises you use. Your stats are a summary of your time and exercise. You can see what percent of the time you stayed inside of the sensitivity you selected.
For example, if you were practicing the rib anchor using the Upright & Relaxed setting, using a 5% sensitivity, you would be able to see what you were practicing, how long you practiced, and how long you managed to stay within the 5% range.