-99.38% is the change from 645 to 4
Calculation steps:
[( 4 - 645 ) ÷ 645] x 100 = -99.38%
Formula
Percentage change = [(4 - 645) / 645] x 100
Subtract the new number by the original number
4 - 645 = -641
-641 ÷ 645 = -0.993798449612403
-0.993798449612403 x 100 = -99.38%