They're mistaken. Roughly 40% of European VC money is invested in London, nowhere else comes even close.
If you just want to do a headcount you can search Crunchbase by city.
Re:YC NYC, September 26
by SoftwarePatent on Tuesday August 16, 2011 @12:06AM
(#2889831)
What is the Paris startup scene like? Can a native English speaker with a little French get a job there? (Especially one with an EU passport ;)
I understand that the language barrier can be stressful for Americans. London is therefore the default choice.