This plot, "Trends in the Academic Labor Force," shows that the percent of academics in tenured or tenure-track positions in the US declined from 39% (29% tenur

This plot, "Trends in the Academic Labor Force," shows that the percent of academics in tenured or tenure-track positions in the US declined from 39% (29% tenured, 10% tenure-track) in 1975 to 29% (21% tenured, 8% tenure-track) in 2015: https://www.aaup.org/sites/default/files/Academic_Labor_Force_Trends_1975-2015.pdf https://www.aaup.org/sites/default/files/Academic_Labor_Forc... The relative number of tenured positions declined by much more (-28%) than the relative number of people in tenure tracks (-20%), so the latter have been facing more and more competition for a shrinking pool of tenured positions.