-41.7% is the change from 530 to 309
Calculation steps:
[( 309 - 530 ) ÷ 530] x 100 = -41.7%
Formula
Percentage change = [(309 - 530) / 530] x 100
Subtract the new number by the original number
309 - 530 = -221
-221 ÷ 530 = -0.4169811320754717
-0.4169811320754717 x 100 = -41.7%