-100...... you know what, even a simple minus doesn't cut it. Fail.
People will argue about what breakdown rates were, whether those the lack of maintenence should be taken into consideration, whether running out of gas qualifys as a breakdown, etc.
Whoever doesn't like the Axis, doesn't like german rides, whoever gets killed by one, and his squadies will be bringing up anecdotal evidence and procede to ignore the context of those stories and actuall history. Untill things started falling apart at the seams, the Tiger I and II weren't much less reliable than the panzer IV or Panther. Differences in operational percentages were within the single digits at times. What killed them was their need for mantiainence, not any inherent reliability issues.
Also, do you count sabotage and poor steel quality? It was documented that the quality of the armor was declining on all german tanks as early as mid 1944. Lacking the materials needed to make high quality steel, the germans did without and built their tanks.
Its quite astounding what they did given the conditions they were under. Say what you will about them or their cause, but they fight hard, and they fight to the end.