-37.83% is the change from 497 to 309
Calculation steps:
[( 309 - 497 ) ÷ 497] x 100 = -37.83%
Formula
Percentage change = [(309 - 497) / 497] x 100
Subtract the new number by the original number
309 - 497 = -188
-188 ÷ 497 = -0.3782696177062374
-0.3782696177062374 x 100 = -37.83%