-73.98% is the change from 638 to 166
Calculation steps:
[( 166 - 638 ) ÷ 638] x 100 = -73.98%
Formula
Percentage change = [(166 - 638) / 638] x 100
Subtract the new number by the original number
166 - 638 = -472
-472 ÷ 638 = -0.7398119122257053
-0.7398119122257053 x 100 = -73.98%