-6.34% is the change from 331 to 310
Calculation steps:
[( 310 - 331 ) ÷ 331] x 100 = -6.34%
Formula
Percentage change = [(310 - 331) / 331] x 100
Subtract the new number by the original number
310 - 331 = -21
-21 ÷ 331 = -0.0634441087613293
-0.0634441087613293 x 100 = -6.34%