If you already got paid proffered wage from your priority date, your case should have no problem in ability-to-pay. And you may not need to submit your company financial document. You can submit your w-2 if your company filed PERM last year and your paystubs in year 2006.
If your company wants to submit its financail document, the following three are the primary documents USCIS seeks to make decision on ability-to-pay:
1. Annual Reports
2. Federal Tax Returns
3. Audited Financial Statements
Hope this is helpful