  The Solar Wind Anisotropies (SWAN) instrument on the SOlar and Heliospheric
Observatory (SOHO) satellite has observed 44 long period and new Oort cloud
comets and 36 apparitions of 17 short period comets since its launch in
December 1995. Water production rates have been determined from the over 3700
images producing a consistent set of activity variations over large parts of
each comet's orbit. This has enabled the calculation of exponential power-law
variations with heliocentric distance of these comets both before and after
perihelion, as well as the absolute values of the water production rates. These
various measures of overall water activity including pre- and post-perihelion
exponents, absolute water production rates at 1 AU, active surface areas and
their variations have been compared with a number of dynamical quantities for
each comet including dynamical class, original semi-major axis, nucleus radius
(when available), and compositional taxonomic class. Evidence for evolution of
cometary nuclei is seen in both long-period and short-period comets.
