-66.88% is the change from 939 to 311
Calculation steps:
[( 311 - 939 ) ÷ 939] x 100 = -66.88%
Formula
Percentage change = [(311 - 939) / 939] x 100
Subtract the new number by the original number
311 - 939 = -628
-628 ÷ 939 = -0.6687965921192758
-0.6687965921192758 x 100 = -66.88%