Accounting for a Performance-Based Stock Option Plan

On January 1, the company granted 155,000 stock options to key employees. Each option allows an employee to buy one share of $1 par common stock for $25, which was the market price of the shares on the grant date of January 1. In order to be able to exercise the options, the employees must remain with the company for three entire years. It is estimated that the fair value of each option on the date of grant was $3. At the end of three years, all of the options were exercised when the market price of the shares was $38 per share. Assume that the stock-based compensation plan is performance based. As of the end of the first year, the number of options that are probable to vest is 155,000. At the end of the second year, the number of options that are probable to vest is 125,000. The options have a 3-year service period.

Make the journal entries necessary at the end of the first year and the second year to recognize the compensation expense associated with this performance-based plan.

end of 1st year	compensation expense	155000
	paid in capital from stock options		155000
end of 2nd year	compensation expense	X
	paid in capital from stock options		X

I need help finding the Xs. The answer is not 125000, 375000, 155000, or 530000

Please explain how you got your answer. Thank you!