Based on this recent CLT Business Journal post the parks attendance for 2017 was “about 2M”. We also added Winterfest that season.
https://www.bizjournals.com/charlotte/news/2019/03/21/photoscarowinds-prepares-to-double-launch-into.amp.html. 2015 the park did pass 2M for that year
https://www.bizjournals.com/charlotte/print-edition/2016/02/26/carowinds-breaks-2-million-mark.amp.html. No mention of anything as high as 2.5M. I believe the chain doesn’t usually give out attendance numbers for specific parks unless it’s a growth they want to show off like Knott’s big 2018 boost.
Seeing as ridership numbers for the top 5 attractions in 2018 all took a dip (Fury - 2017 / 1.5M riders vs 2018 / 1.3M riders), I highly doubt 2018 seen any attendance gains over 2017, the park also lost a few Winterfest days because of weather. So for fun let’s say it was hovering around 2M, I just can’t see the 2019 additions giving the park a 50% year over year boost surpassing 3M guests. Also the last couple weeks of August are running on less days than we are used to seeing.
Anecdotally though does the park seem to have gotten busier year over year since 2015? I know we’ve since added Winterfest but a 2M to 3M jump you would feel in a park our size.