More than twice as many immigrants enter the US legally (1.2 million a year) as illegally. Mexico has an annual population growth rate of 1.1% and a fertility rate of 2.29 children born/woman (2011 est.).
australia is declining,
Not so. Australia has an annual population growth rate of 1.15%, albeit due to immigration.
Mexico’s growth rate would be much higher if mexicans stopped coming to america.