Question: Where does Plymouth's population rank among the cities in the country where the London museum in Trafalgar Square is located?

<P0-S0> London is home to many museums, galleries, and other institutions, many of which are free of admission charges and are major tourist attractions as well as playing a research role. <P0-S1> In 1824 the National Gallery was founded to house the British national collection of Western paintings; this now occupies a prominent position in Trafalgar Square. <P0-S2> The first of these to be established was the British Museum in Bloomsbury, in 1753. <P0-S3> Originally containing antiquities, natural history specimens and the national library, the museum now has 7 million artefacts from around the globe. <SEP> <P1-S0> among other inhabitants of london are 10,000 foxes, so that there are now 16 foxes for every square mile (2.6 square kilometres) of london. <P1-S1> these urban foxes are noticeably bolder than their country cousins, sharing the pavement with pedestrians and raising cubs in people's backyards. <P1-S2> foxes have even sneaked into the houses of parliament, where one was found asleep on a filing cabinet. <P1-S3> another broke into the grounds of buckingham palace, reportedly killing some of queen elizabeth ii's prized pink flamingos. <P1-S4> generally, however, foxes and city folk appear to get along. <P1-S5> a survey in 2001 by the london-based mammal society found that 80 percent of 3,779 respondents who volunteered to keep a diary of garden mammal visits liked having them around. <P1-S6> this sample cannot be taken to represent londoners as a whole. <SEP> <P2-S0> Visitors could use the system to determine which pictures they would like to see in the gallery. <P2-S1> It was possible to print out personalised information for use during the visit. <P2-S2> A micro gallery was a computer-based guide to archives and museum collections, first developed for the collections at the National Gallery in London, UK It took three years to develop by the company Cognitive Applications, and opened in July 1991 as part of the facilities in the Sainsbury Wing. <P2-S3> The Micro Gallery ran for 14 years and a CD-ROM with similar facilities was produced. <SEP> <P3-S0> The city is home to 261,546 (mid-2014 est.) <P3-S1> people, making it the 30th most populous built-up area in the United Kingdom. <P3-S2> It is governed locally by Plymouth City Council and is represented nationally by three MPs. <P3-S3> Plymouth's economy remains strongly influenced by shipbuilding and seafaring including ferry links to Brittany (Roscoff and St Malo) and Spain (Santander), but has tended toward a service-based economy since the 1990s. <P3-S4> It has the largest operational naval base in Western Europe – HMNB Devonport and is home to Plymouth University. <SEP> <P4-S0> the region covers an area of 1,579 square kilometres (610 sq mi). <P4-S1> the population density is 5,177 inhabitants per square kilometre (13,410/sq mi), more than ten times that of any other british region. <P4-S2> in terms of population, london is the 19th largest city and the 18th largest metropolitan region in the world. <P4-S3> as of 2014[update], london has the largest number of billionaires (british pound sterling) in the world, with 72 residing in the city. <P4-S4> london ranks as one of the most expensive cities in the world, alongside tokyo and moscow.