-39.77% is the change from 513 to 309
Calculation steps:
[( 309 - 513 ) ÷ 513] x 100 = -39.77%
Formula
Percentage change = [(309 - 513) / 513] x 100
Subtract the new number by the original number
309 - 513 = -204
-204 ÷ 513 = -0.39766081871345027
-0.39766081871345027 x 100 = -39.77%