You can look at case processing time at the USCIS website. Advise to seek help of an attorney to review your I-90 to make sure you filled out correctly - if it was a USCIS error then you should have it corrected and it should be noted on I-90. Also if it was error of USCIS then you do not have to pay a fee, but again get a good consultation to discuss with an attorney after review of entire record.
No attorney-client relationship is created or implied by this communication.
The length of time to process your green card will depend on the time it takes the USCIS that covers your area. Meet with an immigration attorney to ensure that the form is completed correctly.