Washing is continued for at least ten to fifteen minutes. Junior high schools () are for children aged twelve through fifteen years old. Her vaults were also the best ever achieved by an American aged fifteen and sixteen. Education is free and compulsory between the ages of five and fifteen. The inner integument may consist of eight to fifteen layers. This ad campaign lasted for nearly fifteen years. I attended their meetings for almost fifteen years. Botvinnik participated in championship matches over a period of fifteen years. The crime carries a penalty of one to fifteen years in prison. Tucker worked as a vaudeville straight man at the age of only fifteen years old. Now experimenters find themselves creating scenarios that were impossible to imagine fifteen years ago. In only fifteen minutes he deteriorated rapidly. The censored theatrical version was the only one seen by audiences for fifteen years. He was the youngest of fifteen children. Each episode ran for about fifteen minutes.