27248

I think the results will look like this:

1908 1948 Difference Check point 2012
100m 10.8 secs 10.3 secs 0.5 secs 0.8 secs 9.5 secs
200m 22.6 secs 21.1 secs 1.5 secs 2.4 secs 18.7 secs
400m 50.0 secs 46.2 secs 3.8 secs 6.08 secs 40.2 secs
800m 112 secs 109 secs 3 secs 4.8 secs 104.2 secs
1500m 240 secs 229 secs 11 secs 17.6 secs 211.4 secs

I think the reason for the improvements is that further through time technology has improved to help us become more agile and strong and we have more qualified coaches to train us, also our diet helps us because nowadays we have vitamins and protein shakes but over 40 years ago they had none of them.