srw
It's a bit more complicated than that...
You could, but you would be a bit late to the party.Can I also be pedantic and point out that London, as referred to in the OP, is not actually a city? It's a metropolitan county containing two cities and 31 boroughs. The population of the City of London is not 7.2 million.
The population of Greater London is also not 7.2 million but about 8.1 million.
On a point of order. If the City of Westiminster is on the list with a poopulation of 190,000, then the City of London should be second from bottom with a population of 7,000, not at the top with a population 1000 times bigger.