In all, 97 of 253 episodes produced during the first six years of the programme are not held in the BBC's archives (most notably seasons 3, 4, & 5, from which 79 episodes are missing).
I alt, 97 af 253 episoder produceret i de første seks år af programmet sidder ikke i BBC's arkiver (mest notérligt sæsoner 3, 4, & 5, fra hvilke 79 episoder mangler).