-19.42% is the change from 206 to 166
Calculation steps:
[( 166 - 206 ) ÷ 206] x 100 = -19.42%
Formula
Percentage change = [(166 - 206) / 206] x 100
Subtract the new number by the original number
166 - 206 = -40
-40 ÷ 206 = -0.1941747572815534
-0.1941747572815534 x 100 = -19.42%