Here's a pro-tip, if you are in a company with a lot of employees, negate popular names form your brand campaigns. You'd be amazed at how often someone searches for your brand + Mike, clicks on your ad, then goes down to linkedin in position 1.

If you join your PPC and SEO data, just look for all keywords you spent money on where the #1, 2, or 3 result is linkedin. Sum that total up. Could be thousands or tens of thousands.
Esp. in banking, insurance, etc where you have retail branches.