Incidentally, if you or your husband have assets, those assets can be counted to meet the requirement. In other words, if either of you owns a real estate, for example, you can enter the market value (minus mortgages, etc.) into the form. You can also count secondary vehicles (not your primary one, though).
Also, if you have money in Germany, you (as the applicant) are allowed to include it in the tally.
To give you an idea of what I mean: My wife is a USC and I am the person applying for adjustment of status. My wife has neither income nor any assets. I, however, do - and I can use my assets exclusively to meet the requirement without ever having my wife submit any proof of income/assets.
