From the data, and thank you for linking it, I’d say statistically, the meaningful anomaly is since 2014 and before.
But consider how much has changed in these past 11 years for the sake of entertainment options, and how entertainment is viewed and no longer viewed, especially when today’s adults in their 20s were kids about 15 or younger in 2014 and with many not even teens.
That’s the competition for every pro sports league beyond their own actions, and the ability of each league to adapt to that new reality that is now mainstream and not just the young adults, including to fail to adapt, has also varied in these regards.