text: More than 50 VHE blazar candidates were observed 
  by VERITAS between September 2007 and June 2009. 
  The total exposure on the 49 non-detected candi- 
  dates is ∼305 h live time (average of 6.2 h per can- 
  didate). Approximately 55% of the total exposure is 
  split amongst the 27 observed HBL. The remainder is 
  divided amongst the 8 IBL (26%), 5 LBL (6%), and 9 
  FSRQ (13%). There are no clear indications of signiﬁ- 
  cant VHE γ-ray emission from any of these 49 blazars 
  [25]. However, the observed signiﬁcance distribution is 
  clearly skewed towards positive values (see Figure 1). 
  A stacking analysis performed on the entire data sam- 
  ple shows an overall excess of 430 γ-rays, correspond- 
  ing to a statistical signiﬁcance of 4.8σ, observed from 
  the directions of the candidate blazars. The IBL and 
  HBL targets make up 96% of the observed excess. Ob- 
  servations of these objects also comprise ∼80% of the 
  total exposure. An identical stacked analysis of all 
  the extragalactic non-blazar targets observed, but not 
  clearly detected (>5σ), by VERITAS does not show 
  a signiﬁcant excess (∼120 h exposure). The stacked 
  excess persists using alternate methods for estimating 
  the background at each blazar location, and with dif- 
  ferent event selection criteria (e.g. soft cuts optimized 
  for sources with ΓVHE > 4). The distribution of VHE 
  ﬂux upper limits is shown in Figure 1. These 49 VHE 
  ﬂux upper limits are generally the most-constraining 
  ever reported for these objects. 