-83.9% is the change from 503 to 81
Calculation steps:
[( 81 - 503 ) ÷ 503] x 100 = -83.9%
Formula
Percentage change = [(81 - 503) / 503] x 100
Subtract the new number by the original number
81 - 503 = -422
-422 ÷ 503 = -0.8389662027833003
-0.8389662027833003 x 100 = -83.9%