Understanding my tax statement

I received a plain white tax statement in the mail that says, “Copy 11 For the taxpayer’s reference”. Without disclosing the actual amounts, how can I figure how much could I possibly expect in my return if I’ve been in Taiwan for 365 days in 2012, and have a foreigner wife and 2 daughters here. I’ve never had to pay income tax before since I’ve been in public schools for all the years I’ve been here. What sorts of deductions can I file? Is it best to have someone help my file?
Total amount paid: $xxxxxx
Withholding rate: % (there’s no percentage listed)
Net withholding tax: $xxxxx
Net payment: xxxxxx

Look at page 34 of this pwcjbn.com.tw/pdf/business/tptb.pdf

It also explains deductions somewhere in there. I think you can deduct rent (if you have receipts) and even payments made to NHI and possibly other health related expenses. I’ve never bothered to itemize since even if I had rent receipts I would be right at the standard deduction mark anyways.