Welcome to Open to Export!
Your question intrigued me so after a few hours of light reading I have found the following governmental reports which should be useful:
The above reports contain many points which could be used to support the findings of the Ernst and Young 2013 G20 entrepreneurship barometer.
BIS & UKTI are tasked with the overall business development of the UK, you can read through all of the BIS reports on entrepreneurship here:
The British Chamber of Commerce network is the support system in the UK for SME's, you can read the BCCs quarterly economic reports here:
I hope this helps and good luck with selling Brand GB & your leaflet.