I find this statistic to be amazing, to the point that it is hard to believe.  Below is the Yale Bowl, built on the campus of Yale University in 1914.  At the time of its construction, it was the largest stadium built since the Romans built the colosseum!!  That in turn was finished in 80 AD, 1834 years previously.  That is nearly two millennia it took to build another stadium of comparable size.  What does that tell you about human progress, or the lack of a guarantee of constant improvement that we seem to believe is a given nowadays?