If you have last year's property tax bill from your town/city/county tax assessor's office, you can use that. You can try calling them also (your tax assessor's office). It may also be on last year's Form 1098, if your taxes were in escrow. If you paid by check or credit card, you can check your statements as well.
Click here for Where can I find out how much property (real estate) tax I paid?