WASHINGTON (2/11/11)--Thirty-year fixed-rate mortgages averaged 5.05% during the week ended Feb. 10, the highest average mortgage rate recorded since April 2010, Freddie Mac reported on Thursday. Freddie Mac Vice President/Chief Economist Frank Nothaft said that increasing long-term bond yields “placed upward pressure on mortgage rates.” Thirty-year mortgage rates averaged 4.81% last week. Fifteen-year fixed rate mortgages also increased during the week, averaging 4.29%.Fifteen-year mortgage rates averaged 4.08% last week and 4.34% this time last year. Five-year and one-year adjustable rate mortgages (ARM) also crept up during the week, averaging 3.92% and 3.35%, respectively. Five-year ARMs averaged 4.19% this time last year, while one-year ARMs averaged 4.33%.