-9.2% is the change from 337 to 306
Calculation steps:
[( 306 - 337 ) ÷ 337] x 100 = -9.2%
Formula
Percentage change = [(306 - 337) / 337] x 100
Subtract the new number by the original number
306 - 337 = -31
-31 ÷ 337 = -0.09198813056379822
-0.09198813056379822 x 100 = -9.2%