Area 4
  a          index          b
16.8156   -0.0430315     -10.8937
15.4608   -0.0968477     -9.69878
16.5919   -0.102218      -10.9312

Area 1

9.65930   -0.0583085     -5.27685
13.4776   -0.0693974     -9.47793
14.4904   -0.0489858     -11.4456