  Statistical analyses of the measurements of the Hubble-Lema\^itre constant
$H_0$ (163 measurements between 1976 and 2019) show that the statistical error
bars associated with the observed parameter measurements have been
underestimated -- or the systematic errors were not properly taken into account
-- in at least 15-20\% of the measurements. The fact that the underestimation
of error bars for $H_0$ is so common might explain the apparent discrepancy of
values, which is formally known today as the Hubble tension. Here we have
carried out a recalibration of the probabilities with this sample of
measurements. We find that $x\sigma $ deviation is indeed equivalent in a
normal distribution to $x_{\rm eq.}\sigma $s deviation in the frequency of
values, where $x_{\rm eq.}=0.83x^{0.62}$. Hence, a tension of 4.4$\sigma $,
estimated between the local Cepheid-supernova distance ladder and cosmic
microwave background (CMB) data, is indeed a 2.1$\sigma $ tension in equivalent
terms of a normal distribution of frequencies, with an associated probability
$P(>x_{\rm eq.})=0.036$ (1 in 28). This can be increased up to a equivalent
tension of 2.5$\sigma $ in the worst of the cases of claimed 6$\sigma $
tension, which may anyway happen as a random statistical fluctuation.
