Hotels.com's annual Hotel Price Index (HPI), a measurement of how much travelers pay for overnight accommodations, rose 2% in 2017.

The score of 116 comes the closest the HPI has been to its peak year in 2007, when the HPI reached a score of 118.

Hotels.com's HPI was established in 2004, when it was set at 100. Since then, Hotels.com has been tracking bookings on its sites and issuing a new HPI annually. The HPI is based on what people paid per room, per night based on double occupancy, and includes taxes and fees. Last year's score was 114.

"The slight increase in average accommodation prices globally, combined with a number of markets having record visitor growth, has signaled a strong travel economy and a growing desire from consumers to experience the world," Hotels.com president Johan Svanstrom said in a statement.

The study also ranked destinations. For domestic U.S. travel, Las Vegas was the most popular destination, followed by New York City, Orlando, San Diego and Chicago. For U.S. travelers headed to international destinations, London was the most popular destination, followed by Paris, Toronto, Tokyo and Rome.