  We report the discovery of eight new giant planets, and updated orbits for
four known planets, orbiting dwarf and subgiant stars using the CORALIE, HARPS,
and MIKE instruments as part of the Calan-Hertfordshire Extrasolar Planet
Search. The planets have masses in the range 1.1-5.4MJs, orbital periods from
40-2900 days, and eccentricities from 0.0-0.6. They include a double-planet
system orbiting the most massive star in our sample (HD147873), two eccentric
giant planets (HD128356b and HD154672b), and a rare 14 Herculis analogue
(HD224538b). We highlight some population correlations from the sample of
radial velocity detected planets orbiting nearby stars, including the mass
function exponential distribution, confirmation of the growing body of evidence
that low-mass planets tend to be found orbiting more metal-poor stars than
giant planets, and a possible period-metallicity correlation for planets with
masses >0.1MJ, based on a metallicity difference of 0.16 dex between the
population of planets with orbital periods less than 100 days and those with
orbital periods greater than 100 days.
