Time it takes to transcribe an hour

Hi Everyone

I've just started again in the Transcription world. In my day we called it Audio Typing! My question is this. I am doing about 12 minutes audio to 1 hour typing. If I can't understand something I tend to go over it a few times before marking it unclear and moving on. Am I being particularly slow? I can copy type at around 80 - 85 wpm but that will get faster as I get more work. What is the average time that you guys take? I would appreciate any comments as it will help in planning future work.

Many thanks, Jo