When these were new they were at the dealerships for a LONG LONG time. If I remember this was due to:
The
1979 oil crisis, also known as the
1979 Oil Shock or
Second Oil Crisis, was an
energy crisis caused by a drop in
oil production in the wake of the
Iranian Revolution. Although the
global oil supply only decreased by approximately four percent,
[2] the oil markets' reaction raised the
price of crude oil drastically over the next 12 months, more than doubling it to $39.50 per barrel ($248/m3). The sudden increase in price was connected with fuel shortages and long lines at
gas stations similar to the
1973 oil crisis.
[3]
In 1980, following the onset of the
Iran–Iraq War, oil production in Iran fell drastically.
Iraq's oil production also dropped significantly, triggering
economic recessions worldwide. Oil prices did not return to pre-crisis levels until the mid-1980s.
[4]
Oil prices after 1980 began a steady
decline over the next 20 years, except for a brief uptick during the
Gulf War, which then reached a 60% fall-off in the 1990s. Mexico, Nigeria, and Venezuela's major oil exporters expanded their production during this time. The
Soviet Union became the largest oil producer in the world, and oil from the
North Sea and
Alaska flooded the market.