Yes, you can deduct all property tax you
paid on all property you own in the year paid as long as you only use the property for personal use,
and also itemize your deductions.
So, if you paid 2018 and 2017 property taxes in 2017, you can deduct the amount you actually paid in 2017.
For more details, see:
https://ttlc.intuit.com/questions/1899887-can-i-deduct-real-estate-tax
