-97.04% is the change from 642 to 19
Calculation steps:
[( 19 - 642 ) ÷ 642] x 100 = -97.04%
Formula
Percentage change = [(19 - 642) / 642] x 100
Subtract the new number by the original number
19 - 642 = -623
-623 ÷ 642 = -0.9704049844236761
-0.9704049844236761 x 100 = -97.04%