The following are the returns of a bond portfolio and the returns of a relevant benchmark index for the past 5 years:

Year	Port. Return (%)	Bench. Return (%)
1	8.39	9.46
2	5.54	4.78
3	1.57	2.34
4	6.27	7.93
5	4.39	3.69

What is the tracking risk of this portfolio based on these 5 years? Enter answer in percents.