Conversation so far:
who is affected by a federal government shutdown
Shutdowns cause the disruption of government services and programs, including the closure of national parks and institutions (in particular, due to shortages of federal employees).
how many federal workers were furloughed during the government shutdown
During the government shutdown, approximately 800,000 federal workers have been furloughed or have  been required to work without pay.
what services are affected by a government shutdown
The agencies affected by the government shutdown are Social Security and Medicare, Environmental and Food Inspection, National Parks, Air Travel, Health and Human Services, IRS, and Supplemental Nutrition Assistance Program
how many government shutdowns have there been
There have been four true government shutdowns where operations were affected for more than one business day

Question: what years did the shutdowns happen
Self-contained rewrite: what years did the government shutdowns happen