The ride-sharing app Uber is showing up more than taxis on employee expense reports, according to a new analysis.

The travel and expense management technology provider Certify analyzed business spending in the second quarter of the year for its quarterly Certify SpendSmart Report and found that Uber continues to grow in popularity with business travelers, accounting for 55 percent of ground transportation receipts compared with taxi services at 43 percent.

In the previous quarter, Q1, Uber had 46 percent of receipts compared with taxis at 53 percent. When including rental car data, Uber grew from 8 percent in Q2 of 2014 to 31 percent in Q2 of 2015. During that same 12-month period, taxi usage declined from 37 percent to 24 percent, while rental cars dropped from 55 percent to 45 percent.

The top cities for Uber customers, based on the percentage of receipts, are San Francisco (79 percent), followed by Dallas (60 percent) and Los Angeles (54 percent). Lyft, although comprising only 1 percent of ground transportation receipts, showed growth of 153 percent in ridership over Q1.

Certify also measured business adoption of Airbnb, the fifth most popular online travel-booking site, specializing in online room rentals While receipts from Airbnb are small, Certify’s data shows growth of 143 percent over Q1. Business travelers stay longer in Airbnb accommodations—3.8 nights compared with 2.1 in a hotel—and gave Airbnb a satisfaction rating of 4.72 stars, compared with 4.04 stars for hotels. The cities with the highest percentage of Airbnb bookings by business travelers are, in order, San Francisco, with customers spending an average of $558 per stay, followed by Chicago ($248), Seattle ($221), Miami ($139) and Tampa ($103).

In other categories, the top travel vendors based on percentage of receipts include Starbucks, McDonald’s, Subway, Delta, United, Marriott, Hampton Inn, National and Enterprise.