They are not present in my country. All that matters is just your grades from the Matura exams(think English GCSE exams). It does not matter if you were a golden medalist seven times or ran your own company by the age of 14. On top of that, the Head of the university normally can assign an additional 4 places per year as he/she wishes, so they usually go to people who are talented,but happened to get bad grades in their exams, for any reasons. This is the only moment when your personal circumstances can have any effect on your place at university. Other than that, it does not matter whatever you are rich,poor, white or black - if you got good grades, you will get a place.