aq_cities               Provides a simple listing of cities within the
                        platform.
aq_countries            Provides a simple listing of countries within
                        the platform.
aq_latest               Provides the latest value of each available
                        parameter for every location in the system.
aq_locations            Providing data about distinct measurement
                        locations.
aq_measurements         Function for getting measurements table from
                        the openAQ API
