(Reuters) - Zimbabwe's annual inflation rate, already the highest in the world, has hit 2.2 million percent, central bank Governor Gideon Gono said on Wednesday.

Here are some details on Zimbabwe's inflation milestones and government efforts to control it.

INFLATION'S RISE:

-- Zimbabwe's annual inflation rose above 1,000 percent in April 2006. Official statistics showed the annual inflation rate at a record 1,042.9 percent after 913.6 percent in March.

-- Annualised inflation stood at 3,713.9 percent in April 2007, a monthly rate of increase of 100.7 percent, according to official government data.

-- Inflation slowed in August to 6,592.8 percent from 7,634.8 in July after a price freeze was instituted, but leapt to a record 7,982.1 percent in September.

-- The December 2007 figure had risen to 66,212.3 percent, and by January 2008 it hit 100,586 percent but economic experts said the actual figure was higher.

-- April 2008, the Central Statistics Office reported that in February 2008, the figure stood at 164,900.3 percent.

-- In July 2008 the Central Bank Governor said it is now at 2.2 million percent. Gono said that some independent economists say inflation is 7 million percent annually but the CSO (Central Statistical Office) says 2.2 million percent.