Forecast Fan Chart

{
  "data": [
    { "type":"scatter","mode":"lines","name":"90% upper","x":[0,1,2,3,4,5,6,7,8,9,10],
      "y":[100,103,107,112,118,125,133,142,152,163,175],"line":{"color":"rgba(54,102,255,0)"} },
    { "type":"scatter","mode":"lines","name":"90% lower","x":[0,1,2,3,4,5,6,7,8,9,10],
      "y":[100,100,99,97,94,90,86,82,77,72,67],"fill":"tonexty","fillcolor":"rgba(54,102,255,0.15)","line":{"color":"rgba(54,102,255,0)"} },
    { "type":"scatter","mode":"lines","name":"50% upper","x":[0,1,2,3,4,5,6,7,8,9,10],
      "y":[100,102,104,107,110,114,118,123,128,134,140],"line":{"color":"rgba(54,102,255,0)"} },
    { "type":"scatter","mode":"lines","name":"50% lower","x":[0,1,2,3,4,5,6,7,8,9,10],
      "y":[100,101,100,98,96,94,91,88,85,82,79],"fill":"tonexty","fillcolor":"rgba(54,102,255,0.3)","line":{"color":"rgba(54,102,255,0)"} },
    { "type":"scatter","mode":"lines","name":"Forecast","x":[0,1,2,3,4,5,6,7,8,9,10],
      "y":[100,101.5,102,103,104,105,106,107,108,109,110],"line":{"color":"#3666ff","width":3} }
  ],
  "layout":{"title":"GDP forecast with 50% / 90% bands","xaxis":{"title":"Quarter"},"yaxis":{"title":"Index (Q0 = 100)"}}
}