Fortran used to be more popular. However, TIOBE is a lacking indicator, as stated here: http://pypl.github.io/PYPL.html (do a in-page-search with "Why is PYPL so different from TIOBE ?") Some other indicators such as Redmonk ( https://redmonk.com/sogrady/2019/03/20/language-rankings-1-1... ) show that both Dart and Rust are more popular than Fortran. (Although each of them have their own set of biases.)
I think you mean lagging indicator.
While the page they link to uses "lagging", "lacking" actually seems to fit better with the context it's used in there:
The paragraph it's used in ("Why is PYPL so different from TIOBE ?") seems to argue that TIOBE is lacking, not lagging.
Any sufficiently lagging indicator is also a lacking indicator.