-93.73% is the change from 670 to 42
Calculation steps:
[( 42 - 670 ) ÷ 670] x 100 = -93.73%
Formula
Percentage change = [(42 - 670) / 670] x 100
Subtract the new number by the original number
42 - 670 = -628
-628 ÷ 670 = -0.9373134328358209
-0.9373134328358209 x 100 = -93.73%