Uber has taken people for a lot of rides—two billion, that is, according to CEO Travis Kalanick in a Facebook post today. The milestone comes only six months after Uber said it reached 1 billion rides, an acceleration that highlights the company's global ambitions, as well as its increasing dependence on the biggest prizein the ride-hailing wars: China.

Kalanick said in his post that 147 Uber trips tied for the two billionth ride. These started simultaneously at 4:16 AM GMT in 16 different countries on five continents. The longest ride, a trip in Jakarta, Indonesia, lasted more than an hour, while the shortest was a three-minute trip in Changsha, China. “It took five years to reach our billionth trip, six months to reach the next billion ... and we’ll hopefully reach our third even more quickly,” Kalanick wrote.

That will depend on how effectively Uber competes in its biggest market, China. According to Reuters, 54 of the 147 trips tied for the two billionth ride took place in China. In fact, five of Uber’s 10 top cities by volume are in the country. Unfortunately for Uber, China is also where it's embroiled in a fierce battle with homegrown Chinese rival Didi. In January, Didi said it was operating in more than 400 Chinese cities, where analysts estimate it’s captured about 87 percent of the private ride-hailing market. And, oh, Didi earlier this year said it had booked more than 1.4 billion rides in 2015 alone. (That’s not exactly a parallel comparison to Uber since Didi counts taxi rides, carpooling, buses, and corporate rides, among other services, as part of its tally).

Both companies are raising an enormous amount of financing to stay ahead in China as they bleed money in operations costs. But even as Uber’s spending has reportedly far outpaced its net revenue, the company is at least clearly leading by a few measures. Uber now has more than $13 billion in its cash pile, and it’s valued at $62.5 billion, compared to Didi’s $25 billion valuation. Add 2 billion rides to that list, and Uber can boast it’s ahead in the numbers game. And for now, that's the only game Uber is playing.