...courtesy of Professor Schwitzgebel; this particularly caught my attention:
In general, the humanities have declined sharply since 2010, and history, English, and foreign languages and literature continue to decline. This graph shows the trend:
The decline in the English major is particularly striking, from 4.5% of bachelor's degrees awarded in 2000-2001 to 1.8% in 2021-2022. Philosophy peaked at 0.60% in 2005-2006 and has held steady at 0.39%-0.40% since 2015-2016.
As Professor Schwitzgebel also notes, philosophy has benefitted from a lot of "double majors." The general decline in humanities majors is attributable, one suspects, to the extraordinary cost of higher education, and thus the demand for "marketable" majors. Why this hasn't affected philosophy as much is an interesting question. Thoughts form readers welcome.