Dear All

I appreciate your help with the formula for the following.

I have a table of scores for department per each Month
Period
1 10%
2 25%
3 20%
4 15%
5 30%
6 50%
7 12%
8 22%
9 40%
10 44%
11 56%
12 33%

I need a formula to show me how well this department has performed over the past 12 months , taking into account the fluctuations over time .

Any help with the formula is appreciate it. I don't want to use P12 result -P1 result as it doesn't really show the ups and downs each month

Thanks