-74.3% is the change from 646 to 166
Calculation steps:
[( 166 - 646 ) ÷ 646] x 100 = -74.3%
Formula
Percentage change = [(166 - 646) / 646] x 100
Subtract the new number by the original number
166 - 646 = -480
-480 ÷ 646 = -0.7430340557275542
-0.7430340557275542 x 100 = -74.3%