-95.33% is the change from 642 to 30
Calculation steps:
[( 30 - 642 ) ÷ 642] x 100 = -95.33%
Formula
Percentage change = [(30 - 642) / 642] x 100
Subtract the new number by the original number
30 - 642 = -612
-612 ÷ 642 = -0.9532710280373832
-0.9532710280373832 x 100 = -95.33%