Model df      AIC      BIC    logLik   Test  L.Ratio p-value
    1 11 1319.522 1353.349 -648.7610
    2 12 1320.547 1357.450 -648.2737 1 vs 2 0.974570  0.3235
    3 13 1314.144 1354.121 -644.0720 2 vs 3 8.403558  0.0037
    4 14 1314.880 1357.932 -643.4398 3 vs 4 1.264430  0.2608
    5 15 1316.872 1363.000 -643.4361 4 vs 5 0.007398  0.9315
    6 16 1318.314 1367.517 -643.1569 5 vs 6 0.558260  0.4550
    7 17 1320.067 1372.345 -643.0334 6 vs 7 0.247131  0.6191