More than 207,000 American homes were "flipped" in 2017, the highest annual number since 2006, according to a new report published by the real estate research firm ATTOM Data Solutions. The 2017 total of 207,088 represented a 1 percent increase over the nation's 2016 total and 5.9 percent of all single family home and condo sales. ATTOM defines a property "flip" as any transaction that occurred after a previous sale on the same property had occurred within the previous 12 months.