Kendall tau rank correlations for all pairs of data series
pair	tau	p-value
tau( Y[t] , X[t] )	0.817195404398315	0
tau( Y[t] , Y[t-1] )	0.59750793464206	0
tau( Y[t] , X[t-1] )	0.673493296128661	0
tau( X[t] , Y[t-1] )	0.669844839653346	0
tau( X[t] , X[t-1] )	0.816826724798209	0
tau( Y[t-1] , X[t-1] )	0.818136941553235	0