which assest was the riskiest?

what would you conclude about the realtive risk of investing in small stock?

`	S&P 500	Small Stocks	Corp Bonds	World Portfolio	Treasury Bills	CPI
1991	0.30464	0.38226	0.15869	0.18966	0.05428	0.03064
1992	0.07619	0.2763	0.10642	-0.0466	0.03482	0.02901
1993	0.10079	0.29116	0.14662	0.23129	0.03031	0.02748
1994	0.0132	-0.00138	-0.02435	0.05584	0.04385	0.02675
1995	0.37578	0.32127	0.21991	0.21318	0.05606	0.02538
1996	0.2296	0.1743	0.04239	0.13993	0.05136	0.03322
1997	0.33363	0.18947	0.10847	0.16227	0.0519	0.01702
1998	0.28579	-0.04355	0.10908	0.24795	0.04856	0.01612
1999	0.21042	0.1892	-0.03037	0.25354	0.04802	0.02685
2000	-0.09104	0.0264	0.11694	-0.12928	0.05981	0.03387
Average Ret	18.39%	18.05%	9.54%	13.18%	4.79%	2.66%
Variance	0.021023	0.018917	0.005604	0.015493	7.74E-05	3.23E-05
Std Dev	14.50%	13.75%	7.49%	12.45%	0.88%	0.57%