Occurrences of solar wind plasma with abnormally low proton temperatures (Tp) have long been associated with the interplanetary manifestations (which we term ``ejecta'') of coronal mass ejections (CMEs). We survey the National Space Science Data Center Omni solar wind database for 1965-1991, and data from the Helios 1 and 2 spacecraft for more limited periods, to identify plasma in which Tp is less than the temperature expected (Tex) from the well-established correlation between the solar wind speed and Tp for normal solar wind expansion. The occurrence rate of low-temperature plasma (specifically with Tp/Tex