The number of asylum seekers has fallen for two years - but rose in the six years before that, in line with most of our European neighbours.
The 34,000 arriving in 2004 represented 8.5% of the applicants to the industrialised world.
But the numbers have fallen, not least since regime changes in Afghanistan and Iraq.
Asylum seekers only make up 15% of immigrants each year - and an even smaller proportion of the 5m foreign-born residents of the UK.
It's hard to know for sure how many asylum seekers are genuine refugees as opposed to economic migrants.
Far more applicants are being rejected than before - but about a fifth of those who appeal are later found to be in genuine need.
Removal of failed applicants has increased, but only one in 15 of last year's refusals has been deported.
It is hard to remove people if individuals don't have the documents to be accepted by their home countries.
Through most of the 20th century, more people left the UK than arrived.
Only since 1983 there has been net immigration.
In 2003, 151,000 more people came to the UK for more than a year than left, slightly less than in 2002.
Record numbers of Commonwealth citizens came, along with large numbers of EU citizens and returning Britons, who had been living or working abroad.
140,000 foreign nationals were allowed to settle permanently, meaning they had been here for at least five years.
Almost half of those settling in the UK do so for family reasons such as marriage.
A fifth of settlers start out as long-term workers who later commit to stay.
About 15% are refugees or others given asylum protection.
A third of settlement approvals went to African nationals in 2003 and a fifth to those from the Indian sub-continent.
There are some 1m EU citizens, including Irish, in the UK.
Last year 130,000 people from the EU's new eastern nations came to work in the UK.
There is a lot we don't know because of the way data on migrants is collected.
We lack accurate figures for who comes in and out - and we don't know enough about illegal workers or their skills.
We don't know how many people over-stayed their visas instead of leaving.
And while some failed asylum seekers are removed, others choose to go.
We don't also don't know how much they might contribute to the economy, since asylum seekers are not able to work.
The government suggests migrants put in £2.5bn more in taxes than they take out in benefits - although that figure is tentative and some say it is highly selective.
Advocates believe migration benefits all, including the poor, because cheap labour keeps prices low - not least the cost of public services like the NHS and education.
But sceptics say the poor can lose if they compete with unskilled foreign labour for cheap jobs and housing.
However, many other migrants to the UK are highly skilled.