Toyota has announced that it has cracked the 6 million unit milestone for global hybrid sales.

Toyota announced this week that its official hybrid sales count stood at 6.072 million units as of December 31, 2013, marking a major milestone for both Toyota and the gas-electric technology. Moreover, Toyota said it took just nine months to sell its most recent batch of 1 million hybrids, representing the shortage period in the company’s history to hit that mark.

Toyota began selling hybrid vehicles in late 1997 with the original Prius. Since then, Toyota’s hybrid lineup has grown to include 24 models and one plug-in hybrid. Toyota will launch 15 new hybrid models worldwide over the next two years, including the Highlander Hybrid in the United States.

Toyota estimates that those 6 million hybrids have saved nearly 4 billion gallons of gas and reduced CO2 emissions by 41 million tons.