The 12 month rolling average is useful to compare the month to the average over the past 12 months and it gives us two important pieces of information:
1. Comparison of the month against last 12 months average (better or worse?);
2. The trend of the 12 months average line tells us whether the new month’s KPI is higher or lower than the corresponding month prior year. E.g..: if there’s an upswing for the 12 months average line in 201006, it means that 201006 KPI is higher than 200906 (whether this is good or bad, depends on the nature of the KPI);