Mean changes in CASI Z scores from study entry to assessment at years 1 ( n = 2472 ) , 2 ( n = 1968 ) , 3 ( n = 1521 ) , 4 ( n = 1135 ) , and 5 ( n = 803 ) were 012 ( SD 083 ) , 015 ( 084 ) , 016 ( 095 ) , 019 ( 099 ) , and 014 ( 109 ) , respectively .