-22.24% is the change from 670 to 521
Calculation steps:
[( 521 - 670 ) ÷ 670] x 100 = -22.24%
Formula
Percentage change = [(521 - 670) / 670] x 100
Subtract the new number by the original number
521 - 670 = -149
-149 ÷ 670 = -0.22238805970149253
-0.22238805970149253 x 100 = -22.24%