300 bit per second - 1960s through 1983 or so
1200 bit per second - gained popularity in 1983 - 1985
2400 bit per second - arrived early 1985
9600 bit per second - US Robotics 9600 intro Comdex, 1986
14.4K bit per second -
19.2K bit per second -
28.8K bit per second - 1994
33.6K bit per second -
56K bit per second - became the standard in 1998

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