The worldwide market for public cloud services across all segments grew 20.8% to $91.4 billion in 2011, up from $75.6 billion in 2010. Infrastructure as a service (IaaS) is the fastest-growing segment of public cloud services, with a compound annual growth rate (CAGR) of 41.7% (2011 through 2016). IaaS spending will surpass $72 billion from 2012 through 2016. Growth in the software as a service (SaaS) market is slowing, with annual growth rates of 25.7% in 2011 and 21.3% in 2012 and a five-year CAGR of 17.4%. Emerging Asia/Pacific (including India and Indonesia) has the highest projected growth of all regions, with a 31.8% CAGR, followed by Greater China (30.0%), Latin America (26.4%) and Eurasia (25.9%). Despite high growth rates in emerging countries, spending in North America will account for 61% of total public cloud services spending from 2010 through 2016. Western Europe will have the lowest forecast growth, with an 11.8% CAGR.