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

Question: how many shutdowns have there been
Self-contained rewrite: how many government shutdowns have there been