That will also skew towards shorter tenures, (a) because shorter tenures tend to occur earlier in a career rather than later (so a previous tenure is more likely to have been shorter), and (b) when you’re sampling at a random point within a career, you’re more likely to hit a long tenure within that career, which conversely means that the previous tenure (or more generally, any of the past or future tenures) will more likely be shorter than the current one in that career.