This is a very abnormal vesting schedule. I've never interviewed with a company that has a schedule like that. The most common schedule is 25% per year, over 4 years, vested per month, except that the first 25% comes as a lump as the end of the first year. Most companies provide refreshers every year during the comp cycle. Normally during times when stock prices are low for a company, they'll take that into consideration during the comp cycle and give larger bumps.