the containerboard group ( a division of tenneco packaging inc. ) notes to combined financial statements ( continued ) april 11 , 1999 5 . pension and other benefit plans ( continued ) the funded status of the group 2019s allocation of defined benefit plans , excluding the retirement plan , reconciles with amounts recognized in the 1998 statements of assets and liabilities and interdivision account as follows ( in thousands ) : actuarial present value at september 30 , 1998 2014 .
what is the difference between the weighted average expected long-term rate of return on plan assets for 1998 and the weighted average discount rate used in determining the actuarial present value of the benefit obligations in 1998?
the weighted average discount rate used in determining the actuarial present value of the benefit obligations was 7.00% ( 7.00 % ) for the year ended december 31 , 1998 . the weighted average expected long-term rate of return on plan assets was 10% ( 10 % ) for 1998 . middle management employees participate in a variety of incentive compensation plans . these plans provide for incentive payments based on the achievement of certain targeted operating results and other specific business goals . the targeted operating results are determined each year by senior management of packaging . the amounts charged to expense for these plans were $ 1599000 for the period ended april 11 , 1999 . in june , 1992 , tenneco initiated an employee stock purchase plan ( 2018 2018espp 2019 2019 ) . the plan allows u.s . and canadian employees of the group to purchase tenneco inc . common stock through payroll deductions at a 15% ( 15 % ) discount . each year , an employee in the plan may purchase shares with a discounted value not to exceed $ 21250 . the weighted average fair value of the employee purchase right , which was estimated using the black-scholes option pricing model and the assumptions described below except that the average life of each purchase right was assumed to be 90 days , was $ 6.31 for the period ended december 31 , 1998 . the espp was terminated as of september 30 , 1996 . tenneco adopted a new employee stock purchase plan effective april 1 , 1997 . under the respective espps , tenneco sold 36883 shares to group employees for the period ended april 11 , 1999 . in december , 1996 , tenneco adopted the 1996 stock ownership plan , which permits the granting of a variety of awards , including common stock , restricted stock , performance units , stock appreciation rights , and stock options to officers and employees of tenneco . tenneco can issue up to 17000000 shares of common stock under this plan , which will terminate december 31 , 2001 . the april 11 , 1999 , fair market value of the options granted was calculated using tenneco 2019s stock price at the grant date and multiplying the amount by the historical percentage of past black-scholes pricing values fair value ( approximately 25% ( 25 % ) ) . the fair value of each stock option issued by tenneco to the group in prior periods was estimated on the date of grant using the black-sholes option pricing model using the following ranges of weighted average assumptions for grants during the past three .