"Then, by 2008, the inflation rate had soared to such troubling levels in Zimbabwe that economists were having trouble just figuring out how to measure it. Finally, after wearing out a few calculators, no doubt, Prof. Steve H. Hanke managed to come up with a figure. Prof. Hanke's HHIZ measure indicated that inflation had peaked at an annual rate of 89.7 sextillion percent (89,700,000,000,000,000,000,000%) in mid-November 2008. Gideon Gono, the Governor of the Reserve Bank of Zimbabwe, had achieved a feat that Nero himself could not have imagined possible."
Source: Joel Bowman, "The Daily Reckoning"