What is the normal expense ratio for a MH Park

I find our MH parks run between 32% and 40% depending upon if we bill back utilities to tenants. When we first take over a park the expenses are usually higher. The most recent mobile home park acquisition in Texas had 70%+ expenses… we have already reduced the expenses to 45% in less than 3 months and look to be about 38% by 1st quarter 2006. This has created about $500,000 in equity!