-35.05% is the change from 331 to 215
Calculation steps:
[( 215 - 331 ) ÷ 331] x 100 = -35.05%
Formula
Percentage change = [(215 - 331) / 331] x 100
Subtract the new number by the original number
215 - 331 = -116
-116 ÷ 331 = -0.3504531722054381
-0.3504531722054381 x 100 = -35.05%