-19.48% is the change from 770 to 620
Calculation steps:
[( 620 - 770 ) ÷ 770] x 100 = -19.48%
Formula
Percentage change = [(620 - 770) / 770] x 100
Subtract the new number by the original number
620 - 770 = -150
-150 ÷ 770 = -0.19480519480519481
-0.19480519480519481 x 100 = -19.48%