  We identify the coronal sources of the solar winds sampled by the ACE
spacecraft during 1999-2008, and examine the in situ solar wind properties as a
function of wind sources. The standard two-step mapping technique is adopted to
establish the photospheric footpoints of the magnetic flux tubes along which
the ACE winds flow. The footpoints are then placed in the context of EIT
284~\AA\ images and photospheric magnetograms, allowing us to categorize the
sources into four groups: coronal holes (CHs), active regions (ARs), the quiet
Sun (QS), and "Undefined". This practice also enables us to establish the
response to solar activity of the fractions occupied by each kind of solar
winds, and of their speeds and O$^{7+}$/O$^{6+}$ ratios measured in situ. We
find that during the maximum phase, the majority of ACE winds originate from
ARs. During the declining phase, CHs and ARs are equally important contributors
to the ACE solar winds. The QS contribution increases with decreasing solar
activity, and maximizes in the minimum phase when QS appear to be the primary
supplier of the ACE winds. With decreasing activity, the winds from all sources
tend to become cooler, as represented by the increasingly low O$^{7+}$/O$^{6+}$
ratios. On the other hand, during each activity phase, the AR winds tend to be
the slowest and associated with the highest O$^{7+}$/O$^{6+}$ ratios, and the
CH winds correspond to the other extreme, with the QS winds lying in between.
Applying the same analysis method to the slow winds only, here defined as the
winds with speeds lower than 500 km s$^{-1}$, we find basically the same
overall behavior, as far as the contributions of individual groups of sources
are concerned. This statistical study indicates that QS regions are an
important source of the solar wind during the minimum phase.
