-61.1% is the change from 851 to 331
Calculation steps:
[( 331 - 851 ) ÷ 851] x 100 = -61.1%
Formula
Percentage change = [(331 - 851) / 851] x 100
Subtract the new number by the original number
331 - 851 = -520
-520 ÷ 851 = -0.6110458284371327
-0.6110458284371327 x 100 = -61.1%