 Complete the following phrase:  Phoenix has maintained an expansion streak in recent years, growing by 24.2 before 2007. This made it the second-fastest-expanding metropolitan area in the United States preceded by Las Vegas, whose population had expanded by 29.2 during that time. 2008 was an eventful year in the Valley of the Sun. First, the Phoenix Light Rail would begin operation, with service between Phoenix, Tempe and Mesa. Second, Squaw Peak, the second tallest mountain in the city, was officially renamed Piestewa Peak after Army Specialist Lori Ann Piestewa, an Arizona native who was the first Native American woman to die in combat with the U.S. military, and the first American female casualty in the 