Table 6. A comparison of principal component analyses from three separate data groups (2006 Census Profile, 2005 taxfiler and 2011 taxfiler datasets) pertaining to the census metropolitan area of Guelph performed utilizing only the four income variables.

Source Dataset	Component		Eigenvalue	Difference	Proportion		Cumulative
2006 Census Profile	PC1		2.530160	1.741550	0.6325		0.6325
	C2		0.788604	0.206443	0.1972		0.8297
	C3		0.582160	0.483082	0.1455		0.9752
	C4		0.099079	──	0.0248		1.0000
2005 Taxfiler	PC1		2.908720	2.121430	0.7272		0.7272
	C2		0.787294	0.532456	0.1968		0.9240
	C3		0.254838	0.205690	0.0637		0.9877
	C4		0.049148	──	0.0123		1.0000
2011 Taxfiler	PC1		2.766560	1.929580	0.6916		0.6916
	C2		0.836980	0.485802	0.2092		0.9009
	C3		0.351178	0.305902	0.0878		0.9887
	C4		0.045277	──	0.0113		1.0000
Source Dataset		Indicator Variable				PC1 Variable Loadings
2006 Census Profile		Median Family Income ($)				*0.5257
		Median Single Person Income ($)				0.538
		Low Income Families, After-tax (%)				**-0.4864
		Low Income Unattached, After-tax (%)				-0.4445
2005 Taxfiler		Median Family Income ($)				-0.4477
		Median Single Person Income ($)				-0.5343
		Low Income Families, After-tax (%)				0.557
		Low Income Unattached, After-tax (%)				0.4516
2011 Taxfiler		Median Family Income ($)				-0.4593
		Median Single Person Income ($)				-0.5295
		Low Income Families, After-tax (%)				0.5505
		Low Income Unattached, After-tax (%)				0.4535