Is the income return going to proof I was here for the whole year?
The wage line on your tax return will not show the name of length of employment. If you saved your check stubs, those might prove you were in the US for the times shown on the stubs, or you can try to get confirmation from your employer.
A letter of employment from your employer with dates of employment might be more helpful You can use other documents to show presence also (i.e. school records, medical records, etc.)
Law Offices of J Thomas Smith J.D., Ph.D 11500 Northwest Freeway, Suite 280 Houston, TX 77092 713-LAWYER-2 www.MyImmigrationLawyer.info NOTE: Responses are for the education of the community at large and is not intended to be "legal advice." No attorney-client relationship is established by responses or comments.
You can use it but it is not enough evidence. Pay stubs would be better particularly if you have every one and include all copies in the application package.
The answer provided here is general in nature and does not take into account other factors that may need to be reviewed for a more precise answer. You should consult with an immigration attorney before taking any action. The answer here is not intended to create an attorney-client relationship.