Period	Year	Forward rates
1	0.5	0.9
2	1	1
3	1.5	1.71
4	2	2.21
5	2.5	2.73
6	3	3.25
7	3.5	3.78
8	4	4.32
9	4.5	4.87
10	5	5.43
11	5.5	6.02
12	6	6.62
13	6.5	7.24
14	7	7.89
15	7.5	8.57
16	8	9.29
17	8.5	10.04
18	9	10.84
19	9.5	11.7
20	10	12.63

Find the term stricture of Interest Rates.