Timeline for all types of items produced by
River Soft.

Year	Items
1987	12
1988	3
1989	1
1990	1
1991	2
1992	2
1993	1

22 items with a valid date were considered for this timeline (62.86% of the total)
13 items with an invalid date.

Help us in our quest to find exact dates for:

198?: 13 items.