-66.6% is the change from 931 to 311
Calculation steps:
[( 311 - 931 ) ÷ 931] x 100 = -66.6%
Formula
Percentage change = [(311 - 931) / 931] x 100
Subtract the new number by the original number
311 - 931 = -620
-620 ÷ 931 = -0.6659505907626209
-0.6659505907626209 x 100 = -66.6%