  Based on several tens of Ro measurements made during the past decades,
several studies have been performed to derive the best estimate of Ro. Some
used just simple averaging to derive a result, whereas others provided
comprehensive analyses of possible errors in published results. In either case,
detailed statistical analyses of data used were not performed. However, a
computation of the best estimates of the Galactic rotation constants is not
only an astronomical but also a metrological task. Here we perform an analysis
of 53 Ro measurements (published in the past 20 years) to assess the
consistency of the data. Our analysis shows that they are internally
consistent. It is also shown that any trend in the Ro estimates from the last
20 years is statistically negligible, which renders the presence of a bandwagon
effect doubtful. On the other hand, the formal errors in the published Ro
estimates improve significantly with time.

Astrophysics of Galaxies