662.12% is the change from 66 to 503
Calculation steps:
[( 503 - 66 ) ÷ 66] x 100 = 662.12%
Formula
Percentage change = [(503 - 66) / 66] x 100
Subtract the new number by the original number
503 - 66 = 437
437 ÷ 66 = 6.621212121212121
6.621212121212121 x 100 = 662.12%