-62.15% is the change from 819 to 310
Calculation steps:
[( 310 - 819 ) ÷ 819] x 100 = -62.15%
Formula
Percentage change = [(310 - 819) / 819] x 100
Subtract the new number by the original number
310 - 819 = -509
-509 ÷ 819 = -0.6214896214896215
-0.6214896214896215 x 100 = -62.15%