Timeline for all types of items produced by
DLM [Developmental Learning Materials]

Year	Items
1982	15
1983	12
1984	13
1985	11
1986	2
1987	4
1988	2
1989	7

66 items with a valid date were considered for this timeline (97.06% of the total)
2 items with an invalid date.

Help us in our quest to find exact dates for:

198?: 2 items.