计算数据在此，

	monrthly return =	0.0076987		yearly return =	1.096399
month	contribution	cost basis	gain	after gain
1	100	100	0.769875	100.7699
2	100	200.76987	1.545676	202.3156
3	100	302.31555	2.327451	304.643
4	100	404.643	3.115244	407.7582
5	100	507.75825	3.909102	511.6673
6	100	611.66735	4.709072	616.3764
7	100	716.37642	5.515201	721.8916
8	100	821.89162	6.327536	828.2192
9	100	928.21916	7.146124	935.3653
10	100	1035.3653	7.971015	1043.336
11	100	1143.3363	8.802257	1152.139
12	100	1252.1386	9.639898	1261.778
13	100	1361.7785	10.48399	1372.262
14	100	1472.2624	11.33458	1483.597
15	100	1583.597	12.19171	1595.789
16	100	1695.7887	13.05545	1708.844
17	100	1808.8442	13.92583	1822.77
18	100	1922.77	14.80292	1937.573
19	100	2037.5729	15.68676	2053.26
20	100	2153.2597	16.5774	2169.837
21	100	2269.8371	17.4749	2287.312
22	100	2387.312	18.37931	2405.691
23	100	2505.6913	19.29068	2524.982
24	100	2624.982	20.20907	2645.191
25	100	2745.1911	21.13453	2766.326
26	100	2866.3256	22.06712	2888.393
27	100	2988.3927	23.00688	3011.4
28	100	3111.3996	23.95388	3135.353
29	100	3235.3535	24.90817	3260.262
30	100	3360.2616	25.8698	3386.131
31	100	3486.1314	26.83884	3512.97
32	100	3612.9703	27.81534	3640.786
33	100	3740.7856	28.79936	3769.585
34	100	3869.585	29.79096	3899.376
35	100	3999.3759	30.79018	4030.166
36	100	4130.1661	31.7971	4161.963
37	100	4261.9632	32.81178	4294.775
38	100	4394.775	33.83426	4428.609
39	100	4528.6093	34.86462	4563.474
40	100	4663.4739	35.90291	4699.377
41	100	4799.3768	36.94919	4836.326
42	100	4936.326	38.00352	4974.33
43	100	5074.3295	39.06598	5113.395
44	100	5213.3955	40.13661	5253.532
45	100	5353.5321	41.21549	5394.748
46	100	5494.7476	42.30267	5537.05
47	100	5637.0503	43.39822	5680.448
48	100	5780.4485	44.50221	5824.951
49	100	5924.9507	45.6147	5970.565
50	100	6070.5654	46.73575	6117.301
51	100	6217.3011	47.86543	6265.167
52	100	6365.1666	49.00381	6414.17
53	100	6514.1704	50.15095	6564.321
54	100	6664.3213	51.30692	6715.628
55	100	6815.6282	52.4718	6868.1
56	100	6968.1	53.64564	7021.746
57	100	7121.7457	54.82852	7176.574
58	100	7276.5742	56.0205	7332.595
59	100	7432.5947	57.22167	7489.816
60	100	7589.8164	58.43208	7648.248
61	100	7748.2484	59.6518	7807.9
62	100	7907.9002	60.88092	7968.781
63	100	8068.7812	62.11951	8130.901
64	100	8230.9007	63.36762	8294.268
65	100	8394.2683	64.62535	8458.894
66	100	8558.8936	65.89276	8624.786
67	100	8724.7864	67.16992	8791.956
68	100	8891.9563	68.45692	8960.413
69	100	9060.4133	69.75383	9130.167
70	100	9230.1671	71.06072	9301.228
71	100	9401.2278	72.37767	9473.605
72	100	9573.6055	73.70477	9647.31		1.339904