There's extensive information on how this poll is conducted here. [1] It's a bit different than normal because it's not a one-off survey, but rather a long-term

There's extensive information on how this poll is conducted here. [1] It's a bit different than normal because it's not a one-off survey, but rather a long-term recurring polling. This particular series has been going for 23 years now. I'd guess they added the higher education aspects in 2015 (since that's when the graphs begin). Higher education took a really unexpected turn. We hit 'peak higher education' in 2011 [2], but everybody at the time was expecting it to continue growing rapidly as it had in the decades prior. [1] - https://www.gallup.com/175307/gallup-poll-social-series-methodology.aspx https://www.gallup.com/175307/gallup-poll-social-series-meth... [2] - https://www.statista.com/statistics/183995/us-college-enrollment-and-projections-in-public-and-private-institutions/ https://www.statista.com/statistics/183995/us-college-enroll...