-33.86% is the change from 635 to 420
Calculation steps:
[( 420 - 635 ) ÷ 635] x 100 = -33.86%
Formula
Percentage change = [(420 - 635) / 635] x 100
Subtract the new number by the original number
420 - 635 = -215
-215 ÷ 635 = -0.33858267716535434
-0.33858267716535434 x 100 = -33.86%