-62.8% is the change from 820 to 305
Calculation steps:
[( 305 - 820 ) ÷ 820] x 100 = -62.8%
Formula
Percentage change = [(305 - 820) / 820] x 100
Subtract the new number by the original number
305 - 820 = -515
-515 ÷ 820 = -0.6280487804878049
-0.6280487804878049 x 100 = -62.8%