Last week, Sound Transit released their May ridership numbers, and they hit a big milestone: Daily boardings Seattle’s Link Light Rail surpassed 2 million.

That’s a 14.8 percent increase from May 2016, although May of this year included fewer weekdays.

So far in 2017, according to Sound Transit’s data, Link Light Rail saw more than 9 million boardings—that’s up 40.4 percent from this point in 2016.

For May, average weekday boardings are up 11.9 percent, at 73,208—also a new record. For comparison, King County Metro had 417,396 average weekday boardings that month, and Link is only one route. For a closer comparison, RapidRide had 66,084 average weekday boardings in May—fewer than Link, but for six bus rapid transit lines.

Link saw bigger weekend jumps than weekday, though: 17.1 percent on Saturdays and 16.5 percent on Sundays.

While ridership went up last year, too, there was a big difference in service between May 2015 and May 2016: two new stations in Capitol Hill and at Husky Stadium. After those stations opened in late March of 2016, boardings jumped 79 percent the next month.

May stats for Link. 40% farebox recovery, 92% on time, and 2 new records: 2m total boardings + 73k avg weekday! https://t.co/zU3rK59lnt — Sound Transit (@SoundTransit) July 7, 2017

This year, despite no change in service area, ridership continues to climb significantly. This hasn’t always been the case; Sound Transit first hit the 1 million mark in 2014, and numbers essentially held steady, even dipped a couple of times month over month (which is not unusual), until the new stations opened.

Sound Transit is next scheduled to expand in 2021, with new stations in the U District, Roosevelt, and Northgate.

2023 should be a big year for light rail, with a further stretch north to Mountlake Terrace and Lynnwood, the 10-station East Link to Bellevue and Redmond. The southward extension to Federal Way is scheduled for 2024.

This article has been updated for clarity.