I just came across the following section from an article discussing the print media and reading habits. Can we just say that "the readers have decreased"? Or should we say, 'the number of readers has decreased..."?
"Singer also highlighted that national newspaper readers in the UK have decreased significantly since 2008, a total of 3.1+ million readers have been lost..."
It should say the number of readers has decreased, or better, readership has decreased.
I am not a teacher.