Its all relative.. +/- 5% is pretty huge (even on equality) over the right time period... A change of that amount in anything on the order of a year or less is pretty big.
GDP is a measure of what is produced, with more people in jail or with injuries then those people are not int he workforce, not able to produce things, so GDP goes down, not up. This is true both int he long and short runs, people pulled out of the workforce has **immediate** effect on our ability to produce new foods and produce new wealth.