-87.18% is the change from 515 to 66
Calculation steps:
[( 66 - 515 ) ÷ 515] x 100 = -87.18%
Formula
Percentage change = [(66 - 515) / 515] x 100
Subtract the new number by the original number
66 - 515 = -449
-449 ÷ 515 = -0.8718446601941747
-0.8718446601941747 x 100 = -87.18%