-49.92% is the change from 611 to 306
Calculation steps:
[( 306 - 611 ) ÷ 611] x 100 = -49.92%
Formula
Percentage change = [(306 - 611) / 611] x 100
Subtract the new number by the original number
306 - 611 = -305
-305 ÷ 611 = -0.49918166939443537
-0.49918166939443537 x 100 = -49.92%