in reply to
[OT]: Statistical significance?
If your looking to find if this distribution is likely a uniform distribution, this looks like a job for Chi square test.
Dealing with absolute values (updated from "percentages" to meet what I posted):
Sum of ((observed - expected)^2)/expected)
dividing by df (number of degrees of freedom
Since you have 19 classes, df = 18 the Chi square statistic is:
X-squared = 38297.18, df = 18, p-value < 2.2e-16
And that very small p-value indicates it does
depart significantly from a uniform distribution...
originally got it backwards, as Anonymous Monk pointed out. Hence the following also became a moot point
However if the the same hump was to be observed over and over again, then my suggested approach was probably not the right one to follow,
a real statistician might have a better insight. (That last part still holds ;-)