Juan – congratulations for misrepresenting the argument!
Pedestrians are at greater risk of head injury PER TIME SPENT DOING THAT ACTIVITY (capitals used for the hard of understanding). It is you that fails to understand the statistics.
The problem with all of this is the prevailing and increasing message that cyling is dangerous and that you thus need a helmet. Cycling is not more dangerous than being an urban pedestrian.
Also, if you look into some recent threads you’ll find links to studies which reveal the safety/health balance for cyling, which is MASSIVELY on the side of cycling, despite the very rare injuries.