-92.38% is the change from 840 to 64
Calculation steps:
[( 64 - 840 ) ÷ 840] x 100 = -92.38%
Formula
Percentage change = [(64 - 840) / 840] x 100
Subtract the new number by the original number
64 - 840 = -776
-776 ÷ 840 = -0.9238095238095239
-0.9238095238095239 x 100 = -92.38%