Table: maghreb_countries
Columns: country
area_km
population_millions_2011
gdp_ppp_usd_per_capita
gdp_nominal_billions_usd
hdi_2011

Question: What is the population in millions for 2011 where the HDI for 2011 is 0.453 (low)?
SQL: SELECT "population_millions_2011" FROM maghreb_countries WHERE "hdi_2011" = '0.453 (low)'

Question: What is the population in millions for 2011 where the GDP (nominal) (billions USD) is 4? 
SQL: SELECT "population_millions_2011" FROM maghreb_countries WHERE "gdp_nominal_billions_usd" = '4'

Question: What is the HDI for 2011 in Tunisia? 
SQL: SELECT "hdi_2011" FROM maghreb_countries WHERE "country" = 'Tunisia'

Question: What is the area (km2) where the population in millions for 2011 is 37.1? 
SQL: SELECT "area_km" FROM maghreb_countries WHERE "population_millions_2011" = '37.1'

Question: What is the GDP (PPP) (USD, per capita) for Algeria? 
SQL: SELECT MIN("gdp_ppp_usd_per_capita") FROM maghreb_countries WHERE "country" = 'Algeria'

Question: What is the GDP (nominal) (billions USD) where the population in millions for 2011 is 3.4? 
SQL: SELECT "gdp_nominal_billions_usd" FROM maghreb_countries WHERE "population_millions_2011" = '3.4'