With an income exection or garnishment of salary, does the gross amount include disposable earnings?

In a judgement of income execution I have been instructed to pay or have garnished 10% of my gross salary. The judgement states I am receiving more than $217.50 a week, so is the 10% based on that amount or is the gross considered after federal,state etc is deducted? I have been instructed to send to the Sheriff's Office 10% of my gross each week and a copy of pay slip for that week. What I really asking is what constitutes the amount , the gross with no required deductions or after and what role does the $217.50 play in the entire amount payable to Sheriff or garnishment if I do not comply with the weekly payments.