Source: Intel.
Moore's Law (Transistors per Microprocessor), 1971-2011
In 1965 Gordon Moore, co-founder of the microprocessor manufacturer Intel, predicted that the number of transistors per integrated circuit would double every 18 months. So far his assumption remains reasonably true as microprocessors saw their number of transistors jump from 2,250 in Intel's 4004 (1971) to 731 million in Intel's Pentium iCore 7 (2008) and 2.6 billion for the Xeon (2011). There is thus a doubling every 24 months, which permitted the development of the information economy where massive processing power is required. There are however physical limits to this process as electric current cannot effectively flow once a size threshold is reached.