In July, Uber completed 62 million trips in the U.S., up 15% from 54 million in June, the company told Fortune. And along with completing more than four times as many trips as Lyft, Uber’s growth was also greater than its smaller challenger’s 12% gain over the same period of time, according to a document obtained by tech news site Recode.

The numbers show that both major ride hailing companies are growing, but that one of them—Uber—continues to have a major lead. They also highlight Lyft’s challenge in trying to make inroads after several years of competition.

With that said, Uber’s recent growth spurt could be an anomaly. It’s total number of rides in June represent only an 8% increase from the 50 million trips completed in March.

Similarly, Lyft also had slower growth around that period. As predicted in a similar investor update that recently surfaced, the company’s ride total dipped from May to June. Lyft blamed the drop on seasonality like college students returning home, according to the memo obtained by media outlets. June was also the first full month Lyft has operated since suspending its service in Austin after it lost a battle against the city over a new requirement that drivers be fingerprinted, making gains even tougher to achieve.

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Uber declined to comment about the percentage of its trips that are not subsidized by discounts or credits, which can show how easily it’s attracting customers willing to pay full price for its service. But a source familiar with Uber’s data suggested that even Lyft’s own numbers could be misleading. Both Uber and Lyft offer a carpooling service that often ends up providing solo rides because of a lack of additional passengers. When that happens, the company ends up subsidizing those ride.

According to Lyft’s leaked financials, 81% of Lyft’s rides in July were full-price without discounts or credits, but it’s unclear whether this includes these carpool rides with solo riders and a heavy discount. If so, they could be artificially increasing that percentage.

Our source also said that despite Lyft’s aggressive incentives in New York City since May—half price discounts on all weekday rides for passengers and no commission taken from drivers—Uber has gained an extra 6% of the city’s ride-hailing market since then. But of course, this is only one city.

And while it grew in some cities like New York, it’s also faced challenges in others like Austin, where it shut down its operations in May after residents voted to keep its fingerprinting requirement for drivers. This likely had some negative impact on its business since.

Here are the numbers we have in direct comparison:

• June: Uber’s 54 million U.S. trips, versus Lyft’s 12.4 million
• July: Uber’s 62 million U.S. trips, versus Lyft’s 13.9 million
• Growth from June to June: Uber’s 15% increase in U.S. trips, versus Lyft’s 12% bump.

Aside from its domestic rivalry, Lyft is also currently re-evaluating its partnership with Didi Chuxing, an investor and supposed ally in China, which announced this week plans to acquire Uber’s Chinese business.