How many velodromes are there in the USA?

Could you provide an estimate of the total number of velodromes located within the United States? It's quite an interesting question as cycling, and specifically track cycling, has gained significant popularity in recent years. With the rise of cycling enthusiasts and the establishment of various cycling clubs and events, I'm curious to know if there's been a corresponding increase in the number of velodromes. Could you elaborate on the geographical distribution of these velodromes, if possible? Additionally, are there any plans for future developments or expansions in this area?