Donald Trump’s increasingly polarized run for the presidency has had a clear, negative effect on the businesses in Trump’s namesake empire, according to data published Thursday by the location-tracking technology company Foursquare.

Based on looking at users’ location data in the aggregate, Foursquare found that foot traffic to Trump hotels, golf courses and casinos is down since he announced his candidacy, particularly among women in blue states.

The big data tells an interesting story. Before Trump launched his campaign, infamously calling some Mexicans “rapists,” in June 2015, Foursquare data shows foot traffic had been steady year-over-year and potentially saw an uptick.

But after he became Trump the presidential candidate, Foursquare found his properties didn’t see their usual seasonal boost and, by August 2015, the share of people hoofing it to all Trump properties was down 17 percent from the same period in 2014. After stabilizing to single-digit losses, the start of primary season primetime in March 2016 saw a 17 percent drop in share of people at Trump properties.

The picture is more dire in the breakdown of foot traffic to Trump properties in traditionally red vs. blue states, bearing in mind that Trump properties are located mostly in blue states and rely on guests who live in the region, according to Foursquare. Across Trump locations in New York, New Jersey, Illinois, and Hawaii, foot traffic started to take a hit in March 2016, with the year-on-year share losses widening to 20 percent in July.

The losses were even worse among women, whose visits sustained double-digit losses. In blue states, Foursquare found visits from women to Trump properties were down 29 percent in July.

Foursquare, which operates an app of the same name, offers users suggestions for entertainment, dining and other attractions based on their location and preferences. By analyzing that data, which the company says is anonymized and only viewed in the aggregate, Foursquare has had success predicting broader trends, like hit sales for the launch of McDonald’s all-day breakfast.

According to the company’s Medium post, they draw data from more than 50 million monthly global users across Foursquare, its companion app, Swarm, and its websites. The company compared visits to Trump properties with visits to competitors in the area to analyze changes in market share. Foursquare also said it compared the market share numbers to absolute visits in order to rule out the possibility that its data was skewed by a sudden boost in foot traffic to Trump’s competitors for unrelated reasons – but the downward trend still held. You can read more about the methodology over at Medium.