-13.58% is the change from 670 to 579
Calculation steps:
[( 579 - 670 ) ÷ 670] x 100 = -13.58%
Formula
Percentage change = [(579 - 670) / 670] x 100
Subtract the new number by the original number
579 - 670 = -91
-91 ÷ 670 = -0.13582089552238805
-0.13582089552238805 x 100 = -13.58%