Table 6.

Simulation results of $W_4$.

Year	${\mathit{W}}_4$	${\widehat{\mathit{W}}}_4$	${\mathit{\epsilon }}_4$
2008	404.6	404.6	0
2009	399.7	402.36	−2.6580
2010	400.5	398.29	2.2074
2011	388.9	394.27	−5.3683
2012	397.1	390.28	6.81534
2013	393.8	386.34	7.4587
2014	374	382.44	−8.4377