Thanks guys. I hear what you are saying, but I don't use services like Hotmail, WL, msn for contacts. Facebook, yes, a bit, and I can see those OK in the 'People'.
All my calendar and contact details are held in Apple iCloud service, and I have no contacts in Outlook. I'm confused about where this data has come from (in People) as most of it is years old, with none of my new contacts from the last 2 or 3 years.
Even when I was using Outlook as my main contact tool (up to about 18 months ago), most of the stuff on People had been deleted even then.