-74.34% is the change from 647 to 166
Calculation steps:
[( 166 - 647 ) ÷ 647] x 100 = -74.34%
Formula
Percentage change = [(166 - 647) / 647] x 100
Subtract the new number by the original number
166 - 647 = -481
-481 ÷ 647 = -0.7434312210200927
-0.7434312210200927 x 100 = -74.34%