Populations of the Pacific islands under U.S. jurisdiction are skyrocketing, but departures are holding down growth in Puerto Rico, the Census Bureau reported. Leading in growth was Guam, where net immigration helped boost population between 1980 and 1987 by 24,400, or 23.1%, to 130,400, the bureau said. The Northern Mariana Islands were second, increasing 21.1% to a total of 20,300 people last year. American Samoa added 19% to its population to climb to 38,400. In the Caribbean, the U.S. Virgin Islands grew 9.8% to 106,100 people. However, in Puerto Rico the departure of 227,000 residents between 1980 and 1987 held growth to just 3%, to 3,292,000.