-79.6% is the change from 642 to 131
Calculation steps:
[( 131 - 642 ) ÷ 642] x 100 = -79.6%
Formula
Percentage change = [(131 - 642) / 642] x 100
Subtract the new number by the original number
131 - 642 = -511
-511 ÷ 642 = -0.7959501557632399
-0.7959501557632399 x 100 = -79.6%