id  cadmium          age    vital_c
        9  >10years          61        2.7
        7  >10years          52        2.7
       11  >10years          58       2.73
       10  >10years          65       3.03
       56  None              59       3.03
       50  None              47       3.11
       55  None              62       3.18
       49  None              49       3.31
       14  None              25       3.67
       12  >10years          59       3.67
        4  >10years          41       3.71
       46  None              49       3.76
       35  None              41       3.77
       43  None              48       3.86
       30  None              41       3.88
       52  None              58       3.95
       47  None              54       3.98
       41  None              43       4.02
       34  None              36       4.02
        5  >10years          45       4.02
       38  None              42       4.04
       40  None              41       4.06
       28  None              35       4.09
       36  None              41       4.22
       29  None              35       4.24
        8  >10years          47       4.31
       33  None              36       4.36
       23  None              33       4.44
       18  None              25       4.47
       39  None              39       4.51
       19  None              32       4.55
       53  None              62        4.6
       20  None              18       4.61
        1  >10years          39       4.62
       44  None              47       4.68
       45  None              53       4.74
       51  None              52       4.76
       16  None              32       4.77
       32  None              41       4.79
       54  None              65       4.83
       31  None              38       4.85
       27  None              42       4.89
       37  None              37       4.94
       25  None              33       4.97
       42  None              41       4.99
       26  None              25       4.99
       48  None              48          5
        6  >10years          49       5.09
       22  None              26        5.2
       13  None              27       5.29
        2  >10years          40       5.29
        3  >10years          41       5.52
       24  None              27       5.52
       17  None              23       5.71
       15  None              24       5.82
       21  None              19       5.86