Since the prime bank rate is such a key factor in many financial decisions, I found a history on the web and graphed the January Rate. The average prime rate over the 50 years from 1956 to 2006 was 7.58 %. The extreme range was a low of 3.5 % in 1956 and a high of 20.0 % in 1981. The highest stretch of rates was the seven (7) year period from 1979 to 1985 when the rate never went below 10.5 %. Talk about 7 years of bad luck!
Keep in mind that these are prime rates and fixed rate mortgages are always higher.