-66.51% is the change from 642 to 215
Calculation steps:
[( 215 - 642 ) ÷ 642] x 100 = -66.51%
Formula
Percentage change = [(215 - 642) / 642] x 100
Subtract the new number by the original number
215 - 642 = -427
-427 ÷ 642 = -0.6651090342679128
-0.6651090342679128 x 100 = -66.51%