Record reductions in track records

One of my interests is track athletics, and I am fascinated by reductions in world record times over distances. It impresses me most when there are major reductions in the records, since the record holder has not just been fit and naturally gifted, but has had the mental toughness to do something no-one has come near to before, and in doing so moved the whole sport forward.

Wikipedia has lists of world record progressions from this page; in all events beyond 800 metres, African men feature prominently. The women are less prominently featured, which could be for several reasons. The most substantial recent record reductions by African men are the 1.4 second reduction in the 1500 metres in 1998; the 4.5 second reduction in the 3000 in 1996; the 11 second reduction in the 5000 in 1995; and the minute reduction in the half-marathon in 1993. These would all be the equivalent of a reduction of more than 0.05 second over 100 metres. The 5000 metre reduction is the equivalent of 0.14 seconds off the 100 metres time, and is the largest percentage reduction here. Given when it occurred, in a frequently competed event, and the subsequent competition to reduce it further, it is arguably the most impressive revision of a track record in recent years.