bale    y
    1   52.33
    1   56.26
    1   62.86
    1   50.46
    2   56.99
    2   58.69
    2   58.20
    2   57.35
    3   54.64
    3   57.48
    3   59.29
    3   57.51
    4   54.90
    4   60.08
    4   58.72
    4   55.61
    5   59.89
    5   57.76
    5   60.26
    5   57.53
    6   57.76
    6   59.68
    6   59.58
    6   58.08
    7   60.27
    7   60.30
    7   61.09
    7   61.45