Consider the 20 years (80 quarters) from 1991 through 2010. What business logic led to the distinctions you see below? (i.e. what do "Foo" and "Bar" mean?)
Foo:
1991 Q2 and Q3
1994 Q1
1994 Q4 through 1996 Q3
2000 Q1 through 2001 Q4
2002 Q2 and Q3
2005 Q1
2005 Q4 through 2007 Q4
Bar:
1991 Q1
1991 Q4 through 1993 Q4
1994 Q2 and Q3
1996 Q4 through 1999 Q4
2002 Q1
2002 Q4 through 2004 Q4
2005 Q2 and Q3
2008 Q1 through 2010 Q4
Technically Bar (as seen above) but essentially Foo:
1993 Q1, 1994 Q3, 1999 Q1, 2002 Q1, 2005 Q3, 2008 Q1, 2010 Q1