The complexity for minimum component costs has increased at a rate of roughly a factor of two per year.
G.E. Moore, Elec. Mag., April 1965
Moore's law is really an economic law stating that the density of transistors must double every 18 to 24 months to enable an economic return from the investment in semiconductor foundries (see figure below for historical data). This in turn has knock on effects to the transistor gate length, speed of transistors, power dissipation per gate and microprocessor performance. The semiconductor industry uses scaling to continue down Moore's law, in particular constant power density scaling has been used for many decades.