-84.47% is the change from 644 to 100
Calculation steps:
[( 100 - 644 ) ÷ 644] x 100 = -84.47%
Formula
Percentage change = [(100 - 644) / 644] x 100
Subtract the new number by the original number
100 - 644 = -544
-544 ÷ 644 = -0.84472049689441
-0.84472049689441 x 100 = -84.47%