-83.21% is the change from 393 to 66
Calculation steps:
[( 66 - 393 ) ÷ 393] x 100 = -83.21%
Formula
Percentage change = [(66 - 393) / 393] x 100
Subtract the new number by the original number
66 - 393 = -327
-327 ÷ 393 = -0.8320610687022901
-0.8320610687022901 x 100 = -83.21%