How can I adjust my W-2 reported income, which includes tips I have earned, by the amount I tipped out to other employees?

I am a server employed at a restaurant, and my employer doesn't have a reporting system that accounts for tips I pay to bussers, hostesses, and other servers, even though much of the gratuity sharing is mandated by my employer.  (The "tip-outs" are in cash.) Therefore, my W-2 overstates my income; it doesn't reflect the amount of my tips I paid to other employees.