Twelve years into deployment, and with their fourth version so far.

> The first Superchargers in the world opened in 2012 in the United States. Six stations were deployed along Interstate 5 in California, enabling trips from Los Angeles, California and San Francisco, California and two stations deployed along Interstate 95, enabling trips between Boston, Massachusetts and Washington, DC. By mid-July 2013, 15 stations were open across the United States.

So, a little more than seven - barely - in the first two years of the project, if you count the presumably non-zero time in advance of the first install for construction, permiting, etc.