CREATE TABLE table_28245 ("Metropolitan ring" TEXT, "Localities" FLOAT, "Total" FLOAT, "Jews and others 1" FLOAT, "Thereof: Jews" FLOAT, "Arabs" FLOAT, "Population density  ( per km\\u00b2 ) " TEXT, "Annual Population growth rate" TEXT)

How many time is the population density (per km ) is 2.5?
SELECT COUNT("Localities") FROM table_28245 WHERE "Population density (per km\u00b2)" = '2.5'
SELECT COUNT("Localities") FROM "table_28245" WHERE "Population density (per km\u00b2)" = '2.5'