1977 - The first 7 series was introduced. This was the E23 7 series and it was available
           as 728, 730 and 733i. All models had M30 six cylinders.
1979 - The 728 received fuel injection, the 732i replaced the 730 and the 735i replaced
           the 733i.
1983 - The 745i came available and the 7 series received a small facelift.
1986 - A new 7 series series was introduced. This was the E32 and was available in 730i and
           735i.
1987 - The 750i and 750iL were introduced. The iL was an extra long 7 series. This long
           model was also available as 735iL.
1992 - The 740i replaced the 735i and 735iL. It had a new eight cylinder with 286 HP.
1994 - A new E38 7 series was introduced. There were four models available: the 730i, 740i
           and 750i. The 750i was also available as the extra 750iL.
1996 - The 728i and 728iL six cylinders came available. The 735i and the 735iL replaced the
           730i and the 740i received a new engine.
1997 - The 725tds came available.
1998 - The 730d diesel was introduced.
1999 - The 740d diesel came available.
2001 - There are currently no changes known. But there will be the introduction of a new
           7 Series around March 2001.