A bit of cold water on the game that started with the graph for “philosophy of science” on the HOPOS (history of philosophy of science) list. The cut-off was 2000.
From Alan Richardson, a distinguished scholar in the field and list member.
“If you click on the actual lists for the smoothing periods, you get this: 47,900 hits for “philosophy of science’ in 1992-1995, 69,100 hits for 1996-2000. SO, the use of the term increased almost 50% in database in the period, but the total number of books in the database increased even more rapidly, thus causing the decrease in relative percentage of books using the term.”
So you can get something out of the charts, especially comparing the relative standing of people and topics but the slope of the trend is clearly distorted in the last decade or two.