月份	销售额
2008-01	$ 56,200.00
2008-02	$ 402,370.00
2008-03	$ 396,217.50
2008-04	$ 998,470.00
2008-05	$ 273,800.00
2008-06	$ 662,751.00
2008-07	$ 954,180.00
2008-08	$ 841,313.00
2008-09	$ 62,300.00
2008-10	$ 548,498.00
2008-11	$ 564,126.00
2008-12	$ 274,139.00
2009-01	$ 294,611.00
2009-02	$ 618,988.10
2009-03	$ 1,107,091.40
2009-04	$ 482,419.60
2009-05	$ 792,156.80
2009-06	$ 703,888.90
2009-07	$ 427,747.00
2009-08	$ 582,007.30
2009-09	$ 530,385.48
2009-10	$ 511,895.00
2009-11	$ 1,118,648.50
2009-12	$ 868,240.69
2010-01	$ 837,273.00
2010-02	$ 802,946.00
2010-03	$ 627,884.10
2010-04	$ 558,911.80
2010-05	$ 1,580,109.08
2010-06	$ 962,075.29
2010-07	$ 797,031.86
2010-08	$ 974,035.40
2010-09	$ 900,323.24
2010-10	$ 650,623.00
2010-11	$ 723,836.00
2010-12	$ 2,195,369.95
2011-01	$ 1,646,890.08
2011-02	$ 1,626,268.44
2011-03	$ 1,980,308.69
2011-04	$ 1,677,193.00

如何做接下来几个月的预测？