I submitted a petition for my sister since 12 Feb 2001 and have a NVC case number , every year i write a letter requesting an update, but non-one can tell me how much longer it will take for her to be accepted? does any one knows how to read the chart on Mexico cut-off dates? I would greatly appreciate any suggestions or help on this matter.

You can check status of NVC application online. If you click on "GC Calculator" page on top of this page, you can enter your case number and get the status at NVC.