From CPP's own web site they are getting 10.6% return over the most recent 5 years with an average of 6.8% over 10 years.  I would think they could pass that to us contributors but that's not the case...  Sure the fund is doing well - but we don't get extra.  Still capped at qualifying for the max assuming you earned enough each year to hit the max.
As for where you or anyone else might get 5% annual return - again it comes down to research and learning.  It's out there.  It's common.  Just have to go find it.   

That's like saying I want a cookie but being too lazy to go find the cookie jar...

http://www.cppib.com/en/our-performance/