-90.3% is the change from 639 to 62
Calculation steps:
[( 62 - 639 ) ÷ 639] x 100 = -90.3%
Formula
Percentage change = [(62 - 639) / 639] x 100
Subtract the new number by the original number
62 - 639 = -577
-577 ÷ 639 = -0.9029733959311425
-0.9029733959311425 x 100 = -90.3%