Wiki Employee to Staff Ratio - Occupational Health Clinic

Hello all and thank you for taking the time to view my query. I work for a law enforcement agency with approximately 3000 employees. We have an Occupational Health and Wellness clinic which treats minor acute care issues and also handles external lab orders, external Xray orders, pre-employment physicals, fit-for-duty physicals, and workers comp. My superiors have asked if there is an industry standard ratio for medical clinic size. In other words, how many staff members should the clinic ideally have, given the amount of employees in the agency. I understand there are many variables to this formula, but if anyone can share/ support an approximate industry-standard ratio, it would be GREATLY appreciated Happy holidays!