anchor.diff:  ,,,723070,,,36.82,-72.1,7,7,723070
   ,,,443850,,,43.2,107.17,914,7,443850
   ,,,000732,,,41.43,-121.46,1603,7,000732
  -KBDL,BDL,72508,Hartford,CT,US,41.94,-72.68,60,6,kbdl
  +KBDL,BDL,72508,Windsor Locks,CT,US,41.94,-72.68,60,6,kbdl
   KLAF,LAF,,Lafayette/Purdue,IN,US,40.43,-86.93,182,4,klaf
   ,,,000255,,,46.7,-48.0,0,7,000255
   ,,,915005,,,5.3,132.2,0,7,915005
  
positive.code: KMLS,MLS,74230,Miles City,MT,US,46.44,-105.87,801,4,kmls
  KDVN,DVN,74455,Davenport,IA,US,41.62,-90.58,230,3,dvn
  ,,,915012,,,7.4,149.2,0,7,915012
  KAIA,AIA,,Alliance Muni,NE,US,42.05,-102.8,1196,7,aia
  PAGK,GKN,70271,Gulkana,AK,US,62.15,-145.45,481,6,pagk
  ,,,b#f,,,46.1,-131.0,0,7,b#f
  CYZS,YZS,71915,Coral Harbour,NU,CA,64.2,-83.37,64,5,cyzs
  
negative.code: KEWB,EWB,,New Bedford,MA,US,41.69,-70.97,23,7,kewb
  ,,,lm1,,,45.33,-86.42,177,7,lm1
  ,,,915006,,,8.3,137.5,0,7,915006
  KAPX,APX,72634,Gaylord/Alpena/WFO,MI,US,44.9,-84.7166666667,446,8,apx
  KLIC,LIC,,Limon,CO,US,39.2734,-103.667,1630,4,lic
  KLGB,LGB,72297,Long Beach,CA,US,33.83,-118.15,10,6,klgb
  KFOD,FOD,72549,Fort Dodge,IA,US,42.55,-94.18,355,6,725490
  