While riding the Tube, on way to your first day of internship at a prestigious financial firm in the City of London, you found a torn and dirty piece of paper that was almost illegible. The legible parts are shown below, and are sufficient to remind you of the loans you once studied in a Finance course you took.

Period 1: Beginning Balance (BB): $75,000.00 Payment: $11,007.25 Interest: 7500 Principal: 3507.25 Ending Balance (EB): 71492.75 Period 2: Beginning Balance (BB): $71492.75 Payment: $11,007.25 Interest: 7149.28 Principal: Ending Balance (EB): $67634.78 Period 3: Beginning Balance (BB): $67634.78 Payment: $11,007.25 Interest: 6763.48 Principal: 4243.77 Ending Balance (EB): $63391.01 Assuming that this loan is held to maturity (it does not end early), and assuming that this one of the loan types that we studied, what is the (original) maturity of the loan, in years?