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      Model I:  PTF = β0 +β1G+∈,
        |   | Naive | SE | BC
  | SE | BC
   | SE |  
        | Model    I |  
        | β0 | 38.62 | 0.33 | 38.61 | 0.28 | 38.61 | 0.28 |  
        | β1 | 0.14 | 0.42 | 0.16 | 0.36 | 0.16 | 0.36 |  
        | Model    II |  
        |   β0 | 44.35 | 1.76 | 45.39 | 1.87 | 51.77 | 2.54 |  
        |   β1 | 0.99 | 1.91 | 0.86 | 2.03 | -0.43 | 2.77 |  
        |   β2 | -2.09 | 0.25 | -2.25 | 0.27 | -3.21 | 0.38 |  
        | β3 | -0.11 | 0.31 | -0.09 | 0.32 | 0.13 | 0.45 |  
        | β4 | 0.15 | 0.01 | 0.16 | 0.0 | 0.14 | 0.021 |  
        | Model    III |  
        |   β0 | 45.38 | 1.54 | 46.34 | 1.58 | 51.85 | 1.85 |  
        |   β1 | -0.61 | 1.48 | -0.62 | 1.48 | -0.65 | 1.48 |  
        |   β2 | 0.14 | 0.02 | 0.14 | 0.02 | 0.12 | 0.03 |  
        | β3 | 0.02 | 0.03 | 0.02 | 0.03 | 0.02 | 0.03 |  
        | β4 | -2.17 | 0.15 | -2.31 | 0.16 | -3.12 | 0.21 |  Model II:  PTF = β0 +β1 G +β2PA+β3 PA*G +β4Age+∈,
 Model III: PTF = β0 +β1 G +β2 Age +β3 Age*G +β4 PA+∈
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