Timeline for all types of items produced by
Hartley Courseware, Inc.

Year	Items
1981	1
1982	3
1983	17
1984	7
1985	10
1986	18
1987	18
1988	13
1989	11
1990	2
1992	1

101 items with a valid date were considered for this timeline (100.00% of the total)