First of all: I wouldn't trust your statistics. Source?
Second of all: Compared to a small village in Northern Italy, is London unsafe? Yes. Is it simply a centre for crime? No. However, it's a city. All cities have crime; London is safer than some and less safe than others. Be sensible - don't be out alone in the early hours of the morning; don't make yourself an easy target for pickpockets; don't get caught up with certain people, and watch yourself in certain areas and it's fine.
Millions of people live in and commute to London every single day. Plenty of people never experience crime, others will be a victim of it. I really wouldn't worry about it. Just be sensible and you'll be absolutely fine. I don't live in London, but near enough to travel to it easily, and I've never had any problem either alone or in a group. London is really quite a pleasant city.