I have lived and worked abroad for a foreign company for 7 years. I retired mid-2018 and now live in Colombia, SA. I have filed state taxes in previous years because I still had a US property. However, I did not have any US property in 2018. I do receive a pension from the state of Illinois, which I included in my federal return. Do I need to file an Iowa return as a non-resident or can I skip it?