An athletic field is a 42 yd​-by-84 yd ​rectangle, with a semicircle at each of the short sides. A running track 20 yd wide surrounds the field. If the track is divided into eight lanes of equal​ width, with lane 1 being the​ inner-most and lane 8 being the​ outer-most lane, what is the distance around the track along the inside edge of each​ lane?