-92.32% is the change from 664 to 51
Calculation steps:
[( 51 - 664 ) ÷ 664] x 100 = -92.32%
Formula
Percentage change = [(51 - 664) / 664] x 100
Subtract the new number by the original number
51 - 664 = -613
-613 ÷ 664 = -0.9231927710843374
-0.9231927710843374 x 100 = -92.32%