   0.000   Parents deceased                                              0.000                              0.000    Unknown versus both alive     0.000        −0.000 to 0.000   0.000   0.000    −0.000 to 0.000   0.000    One dead versus both alive    0.000        −0.000 to 0.000   0.000   0.000    −0.000 to 0.000   0.000    Both dead versus both alive   