The long-term lightcurves of our six target quasars spanning timelines from 1996 to 2010. Please note the different flux axis scales. For each source we give the fluxes vs. time separatly for the 1.3-mm (here labeled 1-mm for brevity), 2-mm, and 3-mm bands. For each source (except 3C 111) we approximate the most prominent, continuously sampled variations as exponential rises or decays according to S_ν ∝ exp(± t/t_x) (orange lines). Here t is the time, t_x the characteristic rise/decay timescale of the curve labeled x   (x = a,b,c,...). The sign of t is  + t for exponential rises and −t for decays. All parameters are given in the corresponding diagrams.