There could be many reasons, you lost the home mortgage interest deduction, less tax was being withheld, you may have lost credits.
Compare last year to this year to see what numbers changed.
When you print your return, select "Print all forms and worksheets"
Within the documents you will find a 2-year comparison.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"