SALT LAKE CITY — An economic impact study estimates 71,638 people attended some part of the 2017 Sundance Film Festival, which is a 35-percent increase from last year’s attendance of 46,660. But officials are hesitant to stand by this attendance increase.

Utah firm Y2 Analytics conducted the study. The firm used data from a startup to anonymously track individual people in a particular location through their cellphones.

Researchers counted devices that showed up at two or more events during the 11 days, or that stayed at one ticketed event for their duration.

Betsy Wallace, the Sundance Institute’s managing director, doesn’t think attendance grew by 25,000 people this year. She says the firm’s data probably means attendance estimates from previous years were low.

The firm also found the festival generated an estimated $151.5 million to the state in economic impact.