Legal immigration to the U.S. increased from 250,000 in the 1930s, to 2.5 million in the 1950s, to 4.5 million in the 1970s, and to 7.3 million in the 1980s, before resting at about 10 million in the 1990s. Since 2000, legal immigrants to the United States number approximately 1,000,000 per year, of whom about 600,000 are "Change of Status" who already are in the U.S. Legal immigrants to the United States now are at their highest level ever, at just over 37,000,000 legal immigrants. In reports in 2005–2006, estimates of illegal immigration ranged from 700,000 to 1,500,000 per year. Immigration led to a 57.4% increase in foreign born population from 1990 to 2000.