The cash flows below contain the year 1 cash flows for a potential real estate investment. What is the property's operating expense ratio? Year 1 Number of Units 75 Average Rent $800 Potential Gross Income $720,000 Vacancy and Collection Losses ($72,000) Effective Gross Income $648,000 Operating Expenses ($243,389) Capital Expenditures ($19,440) Net Operating Income $385,171 Annual Debt Service ($323,301) Before-Tax Cash Flow $61,870