That is not how I read it:
QUOTE
You may include evidence supporting your claim about your expected income for the current year if you believe that submitting this evidence will help you establish ability to maintain sufficient income. You are not required to submit this evidence, however, unless specifically instructed to do so by a Government official. For example, you may include a recent letter from your employer, showing your employer's address and telephone number, and indicating your annual salary. You may also provide pay stub(s) showing your income for the previous six months. If your claimed income includes alimony, child support, dividend or interest income, or income from any other source, you may also include evidence of that income.
http://www.uscis.gov/files/form/I-864EZ.pdfNote the words "for example" and "may" this means these things are optional.
I included the employer letter, and copies of a few recent pay stubs, not 6 months.