  Based on high-resolution spectra obtained during gravitational microlensing
events we present a detailed elemental abundance analysis of 32 dwarf and
subgiant stars in the Galactic bulge. [ABRIDGED], we now have 58 microlensed
bulge dwarfs and subgiants that have been homogeneously analysed. The main
characteristics of the sample and the findings that can be drawn are: (i) The
metallicity distribution (MDF) is wide and spans all metallicities between
[Fe/H]=-1.9 to +0.6; (ii) The dip in the MDF around solar metallicity that was
apparent in our previous analysis of a smaller sample (26 microlensed stars) is
no longer evident; instead it has a complex structure and indications of
multiple components are starting to emerge. [ABRIDGED]; (iii) The stars with
[Fe/H]<-0.1 are old with ages between 10 and 12 Gyr; (iv) The metal-rich stars
with [Fe/H]>-0.1 show a wide variety of ages, ranging from 2 to 12 Gyr with a
distribution that has a dominant peak around 4-5 Gyr and a tail towards higher
ages; (v) There are indications in the [alpha/Fe] - [Fe/H] that the "knee"
occurs around [Fe/H] = -0.3 to -0.2, which is a slightly higher metallicity as
compared to the "knee" for the local thick disk. This suggests that the
chemical enrichment of the metal-poor bulge has been somewhat faster than what
is observed for the local thick disk. The results from the microlensed bulge
dwarf stars in combination with other findings in the literature, in particular
the evidence that the bulge has cylindrical rotation, indicate that the Milky
Way could be an almost pure disk galaxy. The bulge would then just be a
conglomerate of the other Galactic stellar populations (thin disk, thick disk,
halo, and ...?), residing together in the central parts of the Galaxy,
influenced by the Galactic bar.
