sentences:  ZiU's production of the MTB-82d lasted from 1951 to 1961, and a total of 3,746 were built (or more than 5,000 when counting the ones built elsewhere, before ZiU was established).In the 1980s, ZiU was building more than 2,000 trolleybuses per year, mostly for domestic use (in the then Soviet Union) but up to 160 per year for export outside the USSR.For many years until at least the early 1990s, ZiU was the world's largest manufacturer of trolleybuses.