Southwest Bancorporation of Texas, Inc. and Subsidiaries
Notes to Consolidated Financial Statements— (Continued)

The fair value of each stock option granted is estimated on the date of grant using the Black-Scholes stock option valuation model with the following weighted-average assumptions for grants in 2000, 1999 and 1998: dividend yield of 0.00% : risk-free interest rates are different for each grant and range from 5.18% to 6.47% ; the expected lives of options range from 5 to 6 years; and a volatility of 29.30% , 28.59% and 26.77% respectively. The weighted average fair value of options granted during the year is as follows:

The following table summarizes information about stock options outstanding and exercisable at December 31, 2000:

If the fair value based method of accounting under SFAS 123 had been applied, the Company’s net income available for common shareholders and earnings per common share would have been reduced to the pro forma amounts indicated below (assuming that the fair value of options granted during the year are amortized over the vesting period) :

The effects of applying SFAS 123 in the above pro forma disclosure are not indicative of future amounts. The Company anticipates making awards in the future under its stock-based compensation plans.

Benefit Plans

The Company has adopted a contributory profit sharing plan pursuant to Internal Revenue Code Section 401(k) covering substantially all employees (the ‘‘401-K Plan") . Each year the Company determines, at its discretion, the amount of matching contributions. The Company presently matches 100% of the employee contributions not to exceed 5.0% of the employee ’ annual compensation. Total plan expense charged to the Company’s operations for the years ended December 31, 2000, 1999 and 1998 was $1,744, $1,374 and $972, respectively.