Here is the file with the Nikuradse data of friction as a function of Reynolds number (Re) and relative roughness.

The first column is Log10[Re] and the second column Log10[f]. 
Where a number in the second column has many decimals, that's 
the first data point for a given roughness. For example:

3.77 0.696000000000000015

is the first data point for a roughness of 15; the data point is
 Log10[Re]=3.77 and Log10[f]=0.696

Now before the data points for a roughness of 15 you'll find about 
30 points that do not correspond to any specific roughness: these 
points describe the hump: they are not tabulated in Nikuradse's paper, 
but they were  measured from the diagram in his paper.

I am grateful to Pinaki Chakraborty and Gustavo Gioia who tabulated
these data.