Anticipated demand in the United Kingdom
In the United Kingdom, the government is reported to have anticipated demand for same-sex civil partnerships as being around 11,000 to 22,000 by 2010. However, this appears to have been an underestimate; as of December 2006 some 15,657 such partnerships had been registered in around 9 months.
Source: http://en.wikipedia.org/wiki/Same_sex_marriage
I would say this is more than just an underestimate but a shows a lack of knowledge by those who compile these kind of reports and statistics.
These are the same people who tell the government the current trends, highs and lows in gay and lesbian lifestyles. They warn the government when "those" people are getting feisty.
They are quite obviously misinformed! So how do we correct it?
PurpleDragon

I think the only way to correct it is to get more people inside, where the stats are compiled, and where the decisions are made.
There is a high proportion of 'married with 2.4 kids and half a labrador, church on Sunday' folk in power just now. It seems to me that a lot of these people are misrepresenting themselves. How many of them continue to go to church on Sunday once they are not in power anymore? How many have lovers of either sex. There should be more 'representative of the population' folk, not in the seats, but in the seats behind the seats - the folk who are in there year in year out, who really make the decisions!
Of course, then the questions is - how to get folk in there?