-49.75% is the change from 609 to 306
Calculation steps:
[( 306 - 609 ) ÷ 609] x 100 = -49.75%
Formula
Percentage change = [(306 - 609) / 609] x 100
Subtract the new number by the original number
306 - 609 = -303
-303 ÷ 609 = -0.4975369458128079
-0.4975369458128079 x 100 = -49.75%