-50.15% is the change from 688 to 343
Calculation steps:
[( 343 - 688 ) ÷ 688] x 100 = -50.15%
Formula
Percentage change = [(343 - 688) / 688] x 100
Subtract the new number by the original number
343 - 688 = -345
-345 ÷ 688 = -0.501453488372093
-0.501453488372093 x 100 = -50.15%