TABLE I.

Differences in X_c and ${\sigma }_2^2$ for simulation cases

sampling time in Xc	${\sigma }_2^2=0.005$	${\sigma }_2^2=0.001$
every 2 years	Case 1a	Case 1b
every 1.5 years	Case 2a	Case 2b/2c
every 1 year	Case 3a	Case 3b