Table 1. General Characteristics of the Subjects.

Data are presented as median (percentile 25, percentile 75) for non-normally distributed variables.

Infant: 6 months-1 year old, toddler: 1-2 years old, preschooler: 3-5 years old.

NS: not significantly different.

^*By Kruskal-Wallis nonparametric test for non-normally distributed variable.

^a-cDifferent alphabets are different by Scheffe's test using ranks for non-normally distributed variables (p<0.05).