While not particularly elegant, you can certainly use it in the way you did. I wouldn't use it to indicate that something included something else. Better to say something like: '70,000 was the number taking part in all events this weekend, and it included those doing the Freecycle.'
Yep, couldn't think of a reason I shouldn't be used, it just read wrong.
Yep, couldn't think of a reason I shouldn't be used, it just read wrong.