Results: The study included 116 patients, 7 children in the group of 2 months - < 1 year old (6.0%), 36 children in the group 1 - < 6 years old (31%), 36 children in the group 6 - < 11 years old (31.1%) and 37 children in the group of 11 - 15 years old (31.9%).