  This work is a continuation of our previous articles (Yermolaev et al. in J.
Geophys. Res. 120, 7094, 2015; Yermolaev et al. in Solar Phys. 292, 193, 2017;
Yermolaev et al. in Solar Phys. 293, 91, 2018), which describe the average
temporal profiles of interplanetary plasma and field parameters in large-scale
solar-wind (SW) streams: corotating interaction regions (CIRs), interplanetary
coronal mass ejections (ICMEs including both magnetic clouds (MCs) and ejecta),
and sheaths as well as interplanetary shocks (ISs). In this work we analyze the
average profile of helium abundance N{\alpha}/Np for interval of 1976-2016. Our
results confirm main early obtained results: N{\alpha}/Np is higher in
quasi-stationary fast streams than in slow ones; it slowly changes in
compression regions CIRs and Sheaths from values in undisturbed solar wind to
values in corresponding type of piston (HSS or ICME); in Ejecta it is closed to
abundance in undisturbed streams and it is maximal in MCs. We obtained for
first time that N{\alpha}/Np correlates with plasma {\beta}-parameter in
compression regions CIRs and Sheaths and anti-correlates in ICMEs. The
N{\alpha}/Np vs. {\beta} dependence is stronger in MCs than in Ejecta and may
be used as an indicator of conditions in CME formation place on the Sun.
