-31.94% is the change from 310 to 211
Calculation steps:
[( 211 - 310 ) ÷ 310] x 100 = -31.94%
Formula
Percentage change = [(211 - 310) / 310] x 100
Subtract the new number by the original number
211 - 310 = -99
-99 ÷ 310 = -0.3193548387096774
-0.3193548387096774 x 100 = -31.94%