Monthly premiums for health insurance coverage through Illinois’ online marketplace are trending downward for the third year in a row as the midnight Tuesday deadline approaches for the federal Affordable Care Act’s open-enrollment period. It’s unclear whether the national recession and rise in unemployment connected with the COVID-19 pandemic will interrupt the four-year decline in enrollment by Illinoisans in federally subsidized and unsubsidized coverage on HealthCare.gov. But a snapshot of signups from this point in the open-enrollment period compared to a similar point last year shows a 3.3% increase in daily average signups in Illinois, according to Stephani Becker, associate director for health care justice at the Chicago-based Shriver Center on Poverty Law.