I don't think you're really helping anybody here Norman!
The difference between section 18 and 20 of the offenses against the person act is for the main one of intent.
It's a rather important difference because section 18 carries a maximum of life whereas section 20 has a maximum of 5 years.
If you take a look down this thread
http://www.theanswerbank.co.uk/News/Question38 2129.html
You'll see I've posted some stats where basically about a third of cases got community service and something over a half got a custodial sentence.
I'd talk to a lawyer if I were you!