The market value of the bond portfolio of an investment fund is $86,827,931 . The duration of the portfolio is 7.33. Based on the analysis provided by the in-house economists, the portfolio manager believes that the interest rates are likely to have an unexpected increase over the next months. Based on this belief, the manager has decided to decrease the duration of its entire bond portfolio to 6.31. The futures contract it would use is priced at $113,681 and has a duration of 4.25. Assume that the conversion factor for the futures contract is 1.05. Approximately, how many futures contracts would be needed to change the duration of the bond portfolio? A positive number indicates buying contracts and a negative number indicates selling contracts.