How to improve prediction using 18-point moving average?

Hi Forum,

Could anybody help me on this?

I have a monthly data series for the past 35 months (pl see attached book1.xls).

Based on this, my boss asked me to predict the expenditure for the next 25 months.

I have used a simple 18-point moving average method to do these predictions.

Question.
As is seen in the chart (pl see attached book1.xls), there is a big jump in the initial month of predicted data, otherwise the predicted series looks not too bad.

How could I get rid of this jump (or is there a better alternative method to do the prediction with precision?)

Appreciate your help
Mirisage