"O 2 said shortly before the iPhone's UK launch on November 9 that it expected handset sales of 200,000 in the first two months, but people familiar with the situation said the actual figure for the first eight weeks was about 190,000."
2 months: 9 Nov to 8 Jan = 61 days
8 weeks = 56 days
190,000 in 56 days = 3393/day. At that rate they'd have sold 206,900 or so in the 61 days that make up the two months.