Productivity Ratio For Recruiters

Is there any defined methods from which we can calculate effectively the productivity ratio of a recruiter, which can measure how productive she/he is to close postions. does it depend on levels of recruitment (sr, middle, low level positons).
Can u help me out in this.

Thanks for ur time dat u shared with me. I think u can help me out to solve my query related to calculate the actual Productivity ratio of a recruiter. Dis all gave me an idea abt all measures that shd be consider / all fields dat hav to consider while we think of productivity. In case of a Recruiters performance i am still vague not able to come into a concultion how we can turn it into a fruitful measurement?