-87.05% is the change from 664 to 86
Calculation steps:
[( 86 - 664 ) ÷ 664] x 100 = -87.05%
Formula
Percentage change = [(86 - 664) / 664] x 100
Subtract the new number by the original number
86 - 664 = -578
-578 ÷ 664 = -0.8704819277108434
-0.8704819277108434 x 100 = -87.05%