Underground debuted in March with record-breaking ratings for WGN America, and it looks to have wrapped up its first season with some pretty strong results.

With Live + 3 numbers now in, the May 11 Season 1 finale of the series about Georgia plantation slaves who dash for their freedom via the Underground Railroad drew 1.8 million viewers. Underground’s 10 PM season ender also had 911,000 viewers among adults 25-54 and 866,000 among the 18-49 demo. That’s a surging percentage rise of 76% in total viewers and 81% and 80% in the respective demos for the Misha Green- and Joe Pokaski-created and EP’d series over its Live + Same Day.

Over four airings last week, the Underground finale had 2.5 million viewers in L+3

While down 22% in viewers and 8% in the 25-54 demo from the L+3 number for the March 9 series premiere, the 10 PM Underground finale was almost even with its May 4 penultimate episode. Underground’s season ender was also up 19% in total viewers over the April 19 Season 1 finale of WGN’s other new drama of the season Outsiders in L+3. With 3 million viewers on average in Live +7 viewing, finale exempt of course, the Jurnee Smollett-Bell- and Aldis Hodge-led series is outpacing the channel’s primetime season average by 506% in total viewers, 918% among the 25-54s and 1,100% among Adults 18-49 so far.

Renewed late last month, Underground‘s second season is set to debut in 2017.