Since I started working night shifts, I have read on average two books a week.
As others have said, the amount of time spent reading depends on the book in your hand. I recently picked up two books by David Baldacci for this week and just finished the second one tonight - His style is stellar, keeps me hooked and I can read for 5 hours solid some nights.
https://en.wikipedia.org/wiki/The_Innocent_(Baldacci_novel) https://en.wikipedia.org/wiki/The_Target_(novel)