-19.11% is the change from 790 to 639
Calculation steps:
[( 639 - 790 ) ÷ 790] x 100 = -19.11%
Formula
Percentage change = [(639 - 790) / 790] x 100
Subtract the new number by the original number
639 - 790 = -151
-151 ÷ 790 = -0.1911392405063291
-0.1911392405063291 x 100 = -19.11%