The latest numbers show heroin and other opiates are still big problems in Minnesota - especially among young people.  A new state report says heroin use is a trend that began about ten years ago and is still growing.  Minnesota drug abuse expert Carol Falkowski says heroin is entering the U-S in large amounts and is popular because of its relatively low street price.  The good news is a drop-off in alcohol, cocaine, meth and tobacco use among students.