-71.3% is the change from 770 to 221
Calculation steps:
[( 221 - 770 ) ÷ 770] x 100 = -71.3%
Formula
Percentage change = [(221 - 770) / 770] x 100
Subtract the new number by the original number
221 - 770 = -549
-549 ÷ 770 = -0.712987012987013
-0.712987012987013 x 100 = -71.3%