392
#&gt;  5:               NA             mean -1.381319138
#&gt;  6:               NA           median -1.341051423
#&gt;  7:               NA             mean -1.188083630
#&gt;  8:               NA           median  0.029939562
#&gt;  9:               NA             mean -0.987419910
#&gt; 10:               NA           median -1.673002281
#&gt; 11:               NA             mean  0.007267359
#&gt; 12:               NA           median  0.127401909
#&gt; 13:               NA             mean -0.17961