Greg Lance has just been informed by a finance company that he can access a line of credit of no more than $75,000 based upon the equity value in his home. Lance still owes $180,000 on a first mortgage against his home and $25,000 on a second mortgage against the home, which was incurred last year to repair the roof and driveway. If the appraised value of Lances residence is $400,000, what percentage of the home's estimated market value is the lender using to determine Lances maximum available line of credit?