share of electricity from Canada. Vermont's 99.9% share of in-state electricity generation from renewable sources was the highest among all 50 states. Health An increasingly aging population is expected to improve the position of aging services and health care in the state economy. The University of Vermont Medical Center, with approximately 6,400 employees, is the largest employer in the state. In 2010, all of Vermont's hospitals billed patients $3.76 billion, and collected $2 billion. 92,000 people are enrolled in Medicare. In 2011, Medicare spent $740 million on health care in the state. Labor In 2009, the state attained a high of 361,290 workers. As of 2006, there were 305,000 workers in Vermont. Eleven percent of these are unionized. Out of a workforce of 299,200 workers, 52,000 were government jobs, federal, state, and local. A modern high unemployment rate of 9% was reached in June 1976. A modern low of 2.4% was measured in February 2000. As of October 2019, the unemployment rate was 2.2%. Employment grew 7.5% from 2000 to 2006. From 1980 to 2000, employment grew by 3.4%; nationally it was up 4.6%. Real wages were $33,385 in 2006 constant dollars and remained there in 2010; the nation, $36,871. Insurance Captive insurance plays an increasingly large role in Vermont's economy. With this form of alternative insurance, large corporations or industry associations form standalone insurance companies to insure their own risks, thereby substantially reducing their insurance premiums and gaining a significant measure of control over types of risks to be covered. There are also significant tax advantages to be gained from the formation and operation of captive insurance companies. According to the Insurance Information Institute, Vermont in 2009 was the world's third-largest domicile for captive insurance companies, following Bermuda and the Cayman Islands. In 2009, there were 560 such companies. In 2010, the state had 900 such companies. Recreation Summer camps such as Camp Abenaki, Camp Billings, Camp Dudley, and Camp Hochelaga contribute to Vermont's tourist economy. In 2005, visitors made an estimated trips to the state, spending . In 2012, fall accounted for $460 million of income, about one-quarter of all tourism. In 2011, the state government earned $274 million in taxes and fees from tourism. 89% of the money came from out-of-state visitors. Tourism supported over 26,000 jobs, 7.2% of total employment. According to the 2000 Census, almost 15% of all housing units in Vermont were vacant and