  We present a statistical investigation of the radial evolution of 28
interplanetary coronal mass ejections (ICMEs), measured in situ by the Parker
Solar Probe (PSP) spacecraft from 2018 October to 2022 August. First, by
analyzing the radial distribution of ICME classification based on magnetic
hodograms, we find that coherent configurations are more likely to be observed
close to the Sun. In contrast, more complex configurations are observed farther
out. We also notice that the post-ICME magnetic field is more impacted
following an ICME passage at larger heliocentric distances. Second, with a
multi-linear robust regression, we derive a slower magnetic ejecta (ME)
expansion rate within 1~au compared to previous statistical estimates. Then,
investigating the magnetic field fluctuations within ICME sheaths, we see that
these fluctuations are strongly coupled to the relative magnetic field strength
gradient from the upstream solar wind to the ME. Third, we identify ME
expansion as an important factor in forming sheaths. Finally, we determine the
distortion parameter (DiP) which is a measure of magnetic field asymmetry in an
ME. We discover lower overall asymmetries within MEs. We reveal that even for
expanding MEs, the time duration over which an ME is sampled does not correlate
with DiP values, indicating that the aging effect is not the sole contributor
to the observed ME asymmetries.
