I would assume it is actual books read, during the winter when I read regularly in the evenings I average a little over 100 pages a day across time. That is a m

I would assume it is actual books read, during the winter when I read regularly in the evenings I average a little over 100 pages a day across time. That is a mixture of fiction and non fiction. That would be 9000 pages in a quarter. Back when I was a more serious reader, for several years I averaged about 50K pages a year. I read fast, but I am by no means the fastest reader I know.