Month n Mean Median SD Range 95% CI 6 53 31.8 31.0 9.04 15.3– 56.7 29.4, 34.3 12 50 31.3 30.5 8.75 16.2– 53.1 28.8, 33.7 18 47 30.7 28.9 9.24 12.6 – 62.1 28.0, 33.5 24 47 31.0 30.6 8.80 16.2– 59.4 28.4, 33.6