-6.04% is the change from 331 to 311
Calculation steps:
[( 311 - 331 ) ÷ 331] x 100 = -6.04%
Formula
Percentage change = [(311 - 331) / 331] x 100
Subtract the new number by the original number
311 - 331 = -20
-20 ÷ 331 = -0.06042296072507553
-0.06042296072507553 x 100 = -6.04%