Traffic lights are being converted from incandescent bulbs to LED arrays to save operating and maintenance costs. Typically each incandescent light uses three 100-W bulbs, one for each color R,Y,G,A competing LED array consists of 61 LEDs with each LED requiring 9V and drawing 20mA of current. There are three arrays per light - R,Y,G,A small city has 1560 traffic signals. Since one light is always on 24/7, how much can a city save in one year if the city buys their electricity at 7.2cents per kWh?