  The known population of exoplanets exhibits a much wider range of orbital
eccentricities than Solar System planets and has a much higher average
eccentricity. These facts have been widely interpreted to indicate that the
Solar System is an atypical member of the overall population of planetary
systems. We report here on a strong anti-correlation of orbital eccentricity
with multiplicity (number of planets in the system) among catalogued radial
velocity (RV) systems. The mean, median and rough distribution of
eccentricities of Solar System planets fits an extrapolation of this
anti-correlation to the eight planet case rather precisely despite the fact
that no more than 2 Solar System planets would be detectable with RV data
comparable to that in the exoplanet sample. Moreover, even if regarded as a
single or double planetary system, the Solar System lies in a reasonably
heavily populated region of eccentricity-multiplicity space. Thus, the Solar
System is not anomalous among known exoplanetary systems with respect to
eccentricities when its multiplicity is taken into account. Specifically, as
the multiplicity of a system increases the eccentricity decreases roughly as a
power law of index -1.20. A simple and plausible but ad hoc and model-dependent
interpretation of this relationship implies that approximately 80% of the one
planet and 25% of the two planet systems in our sample have additional, as yet
undiscovered, members but that systems of higher observed multiplicity are
largely complete (i.e., relatively rarely contain additional undiscovered
planets). If low eccentricities indeed favor high multiplicities, habitability
may be more common in systems with a larger number of planets.
