Between 1874 and 2011, only 78 protected bike lanes existed nationwide. By summer 2016, 292 protected lanes were on the ground across the country, and the number keeps rising.
For the latest figures, view this inventory of protected bike lanes currently in North America. (The file is hosted in Google Drive.) Anyone can sort the data according to their needs by fields such as year built, location, length of lane, and the type of protection offered by the lane, or download it to modify it however they'd like. The inventory is updated regularly with new information on protected lanes.
The graphic below is based on figures from National Protected Bike Lane Week in May 2016.