-2.53% is the change from 790 to 770
Calculation steps:
[( 770 - 790 ) ÷ 790] x 100 = -2.53%
Formula
Percentage change = [(770 - 790) / 790] x 100
Subtract the new number by the original number
770 - 790 = -20
-20 ÷ 790 = -0.02531645569620253
-0.02531645569620253 x 100 = -2.53%