Figure 15: Tonsillotomy (OPS code: 5-281.5), prevalence. The graphs indicate the prevalence (y-axis) between 2007 and 2013 (x-axis), stratified by age groups (x-axis). Since this surgery is performed only rarelyabove the age of 15, not all age groups are depicted. The prevalence constantly increases in the group of 1 to 5 year-old patients since 2007.