Volatility is measurement of the change in price over a given period. It is often expressed as a percentage and computed as the annualized standard deviation of the percentage change in daily price..

 

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Yearly Average
1990	15.3	11.0	23.1	12.3	14.0	11.5	13.2	33.4	19.1	21.1	15.9	15.2	17.1
1991	31.5	13.9	8.8	7.8	9.6	10.9	6.9	9.5	10.0	5.9	8.1	11.5	11.2
1992	10.2	6.9	7.4	8.2	4.7	6.1	7.4	13.5	10.0	8.4	6.9	6.1	8.0
1993	5.0	8.9	6.5	10.9	15.2	11.2	13.6	24.2	24.7	10.3	12.7	8.9	12.7
1994	13.1	11.4	12.5	9.5	13.1	12.0	6.9	7.6	7.0	6.1	4.5	5.3	9.1
1995	11.3	4.1	9.5	8.0	6.8	6.2	5.9	4.2	4.9	2.9	7.6	3.8	6.3
1996	8.1	10.6	6.9	6.6	3.9	4.0	4.2	3.6	3.4	4.8	5.5	4.1	5.5
1997	15.6	10.8	12.4	6.5	9.2	7.8	16.1	11.9	8.9	29.0	21.4	15.8	13.8
1998	21.1	15.1	11.6	12.3	9.0	16.6	7.7	12.2	14.6	12.3	10.3	8.7	12.6
1999	10.5	8.2	10.7	7.6	12.3	8.8	11.3	8.0	37.9	35.4	18.6	16.4	15.5
2000	9.9	37.5	13.9	12.0	9.1	19.1	7.2	10.1	9.7	15.1	9.1	9.9	13.5
2001	7.7	13.4	14.8	10.3	24.0	17.1	9.2	11.1	28.7	20.0	9.9	11.8	14.8
2002	11.4	17.6	12.1	11.4	11.4	14.9	18.6	17.6	11.5	10.0	12.5	14.6	13.6
2003	14.1	24.2	19.2	14.7	15.6	19.5	14.7	15.8	13.1	19.3	15.1	7.6	16.1
2004	22.5	19.6	15.6	20.6	17.8	16.4	16.4	15.3	10.9	12.8	11.7	16.7	16.4
2005	10.7	10.5	12.6	10.0	8.0	9.9	8.6	12.2	11.5	14.2	12.4	18.1	11.6
2006	19.5	24.6	16.7	24.0	34.4	37.3	26.8	17.4	22.9	24.6	16.3	13.8	23.2
2007	18.5		16.3	12.0	14.8	14.2	13.1	17.1	11.3	16.1	27.4		16.1
Mean	14.2	14.6	12.8	11.4	12.9	13.5	11.5	13.6	14.4	14.9	12.5	11.1	13.1
High	31.5	37.5	23.1	24.0	34.4	37.3	26.8	33.4	37.9	35.4	21.4	18.1	37.9
Low	5.0	4.1	6.5	6.5	3.9	4.0	4.2	3.6	3.4	2.9	4.5	3.8	2.9