I'm trying to get a count of students that have test scores for a number of years. So what I want is a count of all students where Score is not null for a number of consecutive years 1998 and 1999 and 2000 and 2001 and 2002 and 2003 and 2004. Also I don't want to duplicate the stuidents in the count. So if there were 1000 students I want only the number that had test scores for all seven years.
Thanks for any help.