Does this make sense?

I've written this under the achievements section of my CV/resume:

'Writing a 250-page graduate careers guide, of which over 50,000 copies were distributed to universities around the UK.' 

It's the 'of which' part I'm struggling with. I've read things like https://english.stackexchange.com/questions/322836/how-to-correctly-apply-in-which-of-which-at-which-to-which-etc/322866 but I'm still not sure. Thank you!