-38.7% is the change from 509 to 312
Calculation steps:
[( 312 - 509 ) ÷ 509] x 100 = -38.7%
Formula
Percentage change = [(312 - 509) / 509] x 100
Subtract the new number by the original number
312 - 509 = -197
-197 ÷ 509 = -0.38703339882121807
-0.38703339882121807 x 100 = -38.7%