-99.84% is the change from 645 to 1
Calculation steps:
[( 1 - 645 ) ÷ 645] x 100 = -99.84%
Formula
Percentage change = [(1 - 645) / 645] x 100
Subtract the new number by the original number
1 - 645 = -644
-644 ÷ 645 = -0.9984496124031008
-0.9984496124031008 x 100 = -99.84%