Sample data:
      1 2373 3689 2316 4067  -81.139   79.669  -65.078   78.175     380.00     107.80       7.89         2999 11  3

Value:
1: counter: branch number
2: x0: start x coordinate
3: y0: start y coordinate
4: x1: end x coordinate
5: y1: end y coordinate
6: lon0: start longitude
7: lat0: start latitude
8: lon1: end longitude
9: lat1: end latitude
10: gclen: great circle length
11: gcazi: great circle azimuth
12: twid: width
13: ic: area
14: rc0: region code for start point
15: rc1: region code for end point