Numbers are meaningless unless they have the total police force number.
Wiki says Chicago PD has about 12,000 officers.
When 8% of your force leaves in ten months of one year and nobody wants to work for you, then you’ve got serious problems.
Note that, if you annualize the loss, it is 9.5% of the police officer force. That is serious attrition and only 51 replacements joined. I’d wager they had to really lower standards to attract those 51, too.