June 15 (Reuters) - The U.S. housing market bounced back quickly last year after the pandemic gave some workers the flexibility to work from anywhere - and demand for vacation homes was especially hot, according to a report released on Tuesday by the National Association of Realtors. Sales of existing homes in counties with a higher share of vacation homes rose by 24% on average in 2020, more than double the 11% increase in counties that don’t have a high concentration of vacation homes. Home prices also appreciated more quickly in vacation home counties, gaining an average 14% last year, compared with the average 10% annual increase in non-vacation-home counties. Vacation-home counties were defined as those where at least 20% of the properties are for seasonal or recreational use. As of 2019, about 10% of the 3,143 counties in the United States were vacation-home counties, according to the association. The hottest vacation markets were concentrated in 16 states, including North Carolina, New York, Vermont and Massachusetts. The No. 1 county, based on sales growth, price and days on the market, was Lee County in Florida, which includes cities such as Fort Myers and Cape Coral. In the next hottest market, Oscoda County, Michigan, home sales rose by 54% in 2020 and the median sales price increased by 79%, according to the report. The county, which is about four hours away from Detroit, includes the Huron-Manistee National Forests and Oscoda Beach Park. The increased demand for vacation homes was sparked by the move to work from home and the shift to virtual schooling, which gave families the flexibility to relocate, the researchers said. Buyers in vacation areas were also more likely to make all-cash offers, which accounted for 53% of the vacation home purchases made between January and April of this year, compared with 22% of all existing home sales. (Reporting by Jonnelle Marte; editing by Jonathan Oatis) Our Standards: The Thomson Reuters Trust Principles.