The disruption rate, the frequency at which disruptions take place, in JET was found to drop steadily over the years. Recent campaigns (2005-2007) show a yearly averaged disruption rate of only 6% while from 1991 to 1995 this was often higher than 20%. Beside the disruption rate, the so-called disruptivity, defined as the likelihood of a disruption depending on the plasma parameters, has been determined. The disruptivity of plasmas was found to be significantly higher close to the three main operational boundaries for tokamaks; the low-q, high density and β-limit. The frequency at which JET operated close to the density-limit, increased 6 fold over the last decade, however, only a small reduction in disruptivity was found. Similarly the disruptivity close to the low-q and β-limit was found to be unchanged. The most significant reduction of disruptivity was found far from the operational boundaries, leading to the conclusion that the improved disruption rate is due to a better technical capability of operating JET, instead of safer operations near to the physics limits. The statistics showed that a simple protection system was able to mitigate the forces of a large fraction of disruptions, although it proved to be at present more difficult to ameliorate the heat flux.