Do I have to file Illinois tax if I made 0 dollars in Illinois since I live in Japan.

Expat living in Japan since 2010. I have been diligently filing both fed and il state taxes although I don't make any income in Illinois. Can I stop filing for il state taxes since I don't have any income at all in Illinois.

 

I believe the website states if you file fed income tax you must file Illinois income tax.

Please advise