If it's anything like my 2011 Macbook Pro was then it will last around 7 years, mine died earlier this year. Mac's tend to last longer for some reason, i was very surprised that my Pro lasted as long as it did, considering i use to carry it around University, use it in lectures, edit videos in the editing suit, take it to the university bar and work there for hours at a time, then after graduating i used it for my first job. I will say that i had my use out of it and then some! it was a great machine and what made me fall in love with the Mac 🙂
That's not to downplay my 2012 iMac, i still love that thing as well and again i've had fair use out of it, editing videos in the home office, writing and playing some of my favourite old games 😀 When Apple decide to update the iMac i will be upgrading from my 2012!