Both FAFSA and CSS Profile now use prior prior year.
https://studentaid.ed.gov/sa/about/announcements/fafsa-changes
https://professionals.collegeboard.org/guidance/financial-aid/applications/prior-prior-year
If you will be applying to start college in fall 2018, then you may submit financial aid forms late in 2017 using 2016 financial information.
Due to the one time circumstance of your father’s unemployment in 2016, you should run the net price calculators based on 2017 income and with the assumption of a full year’s income post-2017. Your second year in college financial aid will be based on 2017 financial information, your third year on 2018, etc., so you want to get estimates of future year costs.