-40.7% is the change from 860 to 510
Calculation steps:
[( 510 - 860 ) ÷ 860] x 100 = -40.7%
Formula
Percentage change = [(510 - 860) / 860] x 100
Subtract the new number by the original number
510 - 860 = -350
-350 ÷ 860 = -0.4069767441860465
-0.4069767441860465 x 100 = -40.7%