Life sentences do not always mean life in prison without parole. People with 1 life sentence can get out well before their death if they are paroled. By giving 2 consecutive life sentences, the person begins serving the 2nd one as soon as paroled for the first, thereby making it closer to an actual life sentence.
For skewed distributions, it is quite common to have one tail of the distribution considerably longer or drawn out relative to the other tail. A skewed right distribution is one in which the tail is on the right side. A skewed left distribution is one in which the tail is on the left side. The above histogram is for a distribution that is skewed right. Skewed distributions bring a certain philosophical complexity to the very process of estimating a typical value for the distribution.
A further characterization of the data includes skewness and kurtosis. Skewness is a measure of symmetry, or more precisely, the lack of symmetry. A distribution, or data set, is symmetric if it looks the same to the left and right of the center point. Kurtosis is a measure of whether the data are peaked or flat relative to a normal distribution. That is, data sets with high kurtosis tend to have a distinct peak near the mean, decline rather rapidly, and have heavy tails. Data sets with low kurtosis tend to have a flat top near the mean rather than a sharp peak.