-83.45% is the change from 550 to 91
Calculation steps:
[( 91 - 550 ) ÷ 550] x 100 = -83.45%
Formula
Percentage change = [(91 - 550) / 550] x 100
Subtract the new number by the original number
91 - 550 = -459
-459 ÷ 550 = -0.8345454545454546
-0.8345454545454546 x 100 = -83.45%