Table: irish_sea_cities
Columns: rank
city_town
county
region_province
population
country

Question: When birkenhead is the city/town and merseyside is the county and england is the country how many ranks are there?
SQL: SELECT COUNT("rank") FROM irish_sea_cities WHERE "country" = 'England' AND "county" = 'Merseyside' AND "city_town" = 'Birkenhead'

Question: When 2 is the rank what is the city/town?
SQL: SELECT "city_town" FROM irish_sea_cities WHERE "rank" = 2

Question: When 20 is the rank and north west is the region/province what is the county?
SQL: SELECT "county" FROM irish_sea_cities WHERE "region_province" = 'North West' AND "rank" = 20

Question: When fleetwood is the city/town how many sets of population are there?
SQL: SELECT COUNT("population") FROM irish_sea_cities WHERE "city_town" = 'Fleetwood'

Question: When 142900 is the population what is the highest rank?
SQL: SELECT MAX("rank") FROM irish_sea_cities WHERE "population" = 142900

Question: When 31901 is the population what is the county?
SQL: SELECT "county" FROM irish_sea_cities WHERE "population" = 31901