From Kauffman Report: It Takes Decades to Build a Startup Hub:

Density of ICT Startup in the United States - Source: Ian Hathaway
Density of ICT Startup in the United States – Source: Ian Hathaway

Density of ICT Startup in the United States – Source: Ian Hathaway, “Tech Starts: High-Technology Business Formation and Job Creation in the United States,” Kauffman Foundation Research Series on Firm Formation and Economic Growth, August 2013.