-87.7% is the change from 122 to 15
Calculation steps:
[( 15 - 122 ) ÷ 122] x 100 = -87.7%
Formula
Percentage change = [(15 - 122) / 122] x 100
Subtract the new number by the original number
15 - 122 = -107
-107 ÷ 122 = -0.8770491803278688
-0.8770491803278688 x 100 = -87.7%