Kendall tau rank correlations for all pairs of data series
pair	tau	p-value
tau( TotWL , <25WL )	0.735960169258697	0
tau( TotWL , >25WL )	0.808411354746175	0
tau( TotWL , woningen )	0.122051130768899	0.145389278012317
tau( <25WL , >25WL )	0.53682038577107	2.32063701588459e-10
tau( <25WL , woningen )	0.0223341591724569	0.7907590099565
tau( >25WL , woningen )	0.165872839386846	0.0487353151263528