-66% is the change from 650 to 221
Calculation steps:
[( 221 - 650 ) ÷ 650] x 100 = -66%
Formula
Percentage change = [(221 - 650) / 650] x 100
Subtract the new number by the original number
221 - 650 = -429
-429 ÷ 650 = -0.66
-0.66 x 100 = -66%
Example