No, you cannot update from one year to the next. A TurboTax software product is only good for the one tax year it was written for. Every tax year requires a new product purchase. A 2015 return requires 2015 software; a 2016 return requires 2016 software; etc. Any reference to 5 free Federal efiles means one can efile 5 returns for that same tax year.
You can purchase the Business product from TurboTax at the link below, or you may be able to find it at a discount in a store locally or at reputable authorized retailers such as Amazon, etc.
https://turbotax.intuit.com/small-business-taxes/