  The Large Binocular Telescope Interferometer (LBTI) enables nulling
interferometric observations across the N band (8 to 13 um) to suppress a
star's bright light and probe for faint circumstellar emission. We present and
statistically analyze the results from the LBTI/HOSTS (Hunt for Observable
Signatures of Terrestrial Systems) survey for exozodiacal dust. By comparing
our measurements to model predictions based on the Solar zodiacal dust in the N
band, we estimate a 1 sigma median sensitivity of 23 zodis for early type stars
and 48 zodis for Sun-like stars, where 1 zodi is the surface density of
habitable zone (HZ) dust in the Solar system. Of the 38 stars observed, 10 show
significant excess. A clear correlation of our detections with the presence of
cold dust in the systems was found, but none with the stellar spectral type or
age. The majority of Sun-like stars have relatively low HZ dust levels
(best-fit median: 3 zodis, 1 sigma upper limit: 9 zodis, 95% confidence: 27
zodis based on our N band measurements), while ~20% are significantly more
dusty. The Solar system's HZ dust content is consistent with being typical. Our
median HZ dust level would not be a major limitation to the direct imaging
search for Earth-like exoplanets, but more precise constraints are still
required, in particular to evaluate the impact of exozodiacal dust for the
spectroscopic characterization of imaged exo-Earth candidates.
