anchor.diff:  1971/6/6,"Hughes Airwest Flight 706","","","",34.175,-118,""
   1971/6/7,"Allegheny Airlines Flight 485","","","",0,0,""
   1971/7/3,"Toa Domestic Airlines Flight 533","","","",41.93333333333333,140.78333333333333,""
  -1971/7/30,"All Nippon Airways Flight 58","","","",undefined,undefined,""
  +1971/7/30,"All Nippon Airways Flight 58","","","",,,""
   1971/7/30,"Pan Am Flight 845","","","",0,0,""
   1971/9/4,"Alaska Airlines Flight 1866","","","",58.361666666666665,-135.17,""
   1971/9/6,"Paninternational Flight 112","","","",53.69916666666666,9.913055555555555,""
  
positive.code: 1979/10/8,"Swissair Flight 316","","","",37.87388888888889,23.740833333333335,""
  1979/10/31,"Western Airlines Flight 2605","","","",19.43638888888889,-99.07222222222222,""
  1979/11/15,"American Airlines Flight 444","","","",38.95305555555556,-77.45,""
  1979/11/26,"PIA Flight 740","","","",undefined,undefined,""
  1979/11/28,"Air New Zealand Flight 901","","","",-77.42500000000001,167.45833333333331,""
  1979/12/23,"Turkish Airlines Fokker F28 crashes into a hillside","","","",40.32944444444445,33.15694444444444,""
  1980/1/21,"Iran Air Flight 291","","","",undefined,undefined,""
  1980/2/21,"Advance Airlines Flight 4210","","","",33.94611111111111,-151.1772222222222,""
  1980/3/14,"LOT Flight 7","","","",52.18472222222222,20.949722222222224,""
  1980/4/12,"Transbrasil Flight 303","","","",0,0,""
  
negative.code: 1981/6/26,"Dan-Air Flight 240","","","",52.669444444444444,-1.3702777777777777,""
  1981/7/20,"Somali Airlines Flight 40","","","",0,0,""
  1981/7/27,"Aeromexico Flight 230","","","",0,0,""
  1981/8/13,"G-ASWI North Sea ditching","","","",,,""
  1981/8/22,"Far Eastern Air Transport Flight 103","","","",0,0,""
  1981/8/24,"Aeroflot Flight 811","","","",50.019444444444446,130.46666666666667,""
  1981/8/26,"Aeropesca Colombia Flight 221","","","",0,0,""
  1981/10/6,"NLM CityHopper Flight 431","","","",,,""
  1981/11/17,"Aeroflot Flight 3603","","","",69.29388888888889,87.30083333333333,""
  1981/12/1,"Inex-Adria Aviopromet Flight 1308","","","",41.75416666666667,8.977777777777778,""
  1983/1/16,"Turkish Airlines Flight 158","","","",40.11277777777778,32.980000000000004,""
  