  We have performed a statistical study of $152$ Type III radio bursts observed
by Solar TErrestrial RElations Observatory (STEREO)/Waves between May 2007 and
February 2013. We have investigated the flux density between $125$kHz and
$16$MHz. Both high- and low-frequency cutoffs have been observed in $60\,%$ of
events suggesting an important role of propagation. As already reported by
previous authors, we observed that the maximum flux density occurs at $1$MHz on
both spacecraft. We have developed a simplified analytical model of the flux
density as a function of radial distance and compared it to the STEREO/Waves
data.
