Statistics played a trick on me

Just came back from the dosimetry service at CERN, where I finally got my dosimeter!
Actually I got five !!! Yeah five !!! Cause apparently statistics played a trick on me today.
Out of the ten percent of chips that fail (by definition somehow) I got four IN A ROW.
How unlikely is that … and guess what, you have to wait four to five minutes after each new chip to get registered in the data base … so over the time I became good friends with the guy at the counter ;)