Skolelevers drogvanor - 2009, årskurs 9

Since 1971, a national drug habit survey has been conducted among Swedish ninth graders. From 2004, annual survey are also being conducted among students in the second year of...自1971年起，针对瑞典九年级学生的全国性药物使用习惯调研便已启动并持续开展。自2004年起，同步针对……二年级学生开展年度调研。