Bend was the 35th fastest-growing big city in the U.S. for the year ended last July 1st and also made the top 100 for the period since the April 2010 Census, the Census Bureau reported Thursday. In its new estimates only of cities over 50,000 population, Bend grew by 2,297 residents, to total 81,236, for the year ending last July 1st, a 2.9 percent growth rate that made it the fastest-growing in the state and No. 35 for the nation as a whole. Over the three-year-plus period dating to April 1st, 2010, Bend grew by 4,597 residents, or 6 percent, placing the city at No. 97 in terms of the percentage of growth, the agency said. The Census Bureau population estimate for Bend last July 1st also is sizably ahead of the one issued last fall by Portland State University's Population Resesarch Center, It estimated Bend at 78,280, up 825 residents, or just over 1 percent for the year ended July 1st.