Top: all available submm light curves between 2004 and 2014. The plot contains both the LABOCA data (blue circles) and the literature data (green down-pointing triangles: Eckart et al. 2009; cyan left-pointing triangles: Yusef-Zadeh et al. 2006a; magenta right-pointing triangles: Yusef-Zadeh et al. 2008; yellow squares: Yusef-Zadeh et al. 2009; red up-pointing triangles: Trap et al. 2011). Bottom: a concatenated light curve of the submm data. Time gaps greater than 10 min were replaced by gaps of 300 s.