step_ahead,prediction
1,221.88467
2,221.89886
3,221.83841
4,221.20485
5,222.90112
6,221.97243
7,221.88802
8,222.05893
9,221.71313
10,220.84164
11,221.39264
12,220.69806
13,221.40622
14,221.7423
15,222.00854