The Swedish school system:
Daycare + pre-school: Age 1 to 7
Primary school: Age 7 to 16 (mandatory)
Secondary school: Age 16 to 19
Tertiary school: Optional from the age of 19
I gratuated from secondary school at 18 (I studied to become a children's caretaker) because back then we could choose between educations/courses that took 2-4 years to complete. And at that time tertiary school wasn't a necessity. Today it is and Sweden's become similar to the US in that aspect. If we don't have a university degree it's hard to get work.