-62.86% is the change from 840 to 312
Calculation steps:
[( 312 - 840 ) ÷ 840] x 100 = -62.86%
Formula
Percentage change = [(312 - 840) / 840] x 100
Subtract the new number by the original number
312 - 840 = -528
-528 ÷ 840 = -0.6285714285714286
-0.6285714285714286 x 100 = -62.86%