1 minute = 60 seconds
1 hour = 60 minutes = 60 x 60 seconds = 3600 seconds
1 day = 24 hours = 24 x 3600 seconds = 86400 seconds
1 year = 365 days = 365 x 86400 seconds = 31536000 seconds
Number of years in 1 billion seconds = 1,000,000,000 / 31,536,000 = 31.71 years