Standards for storing a rating as a range (1-5, 1 is best, etc.)

I am designing a ROAD_INSPECTION table that has a CONDITION field: +---------+-----------+ | ROAD_ID | CONDITION | +---------+-----------+ | 1 | 2 | | 2 | 5 | | 3 | 1 | | 4 | 1 | | 5 | 4 | +---------+-----------+ Are there any standards or conventions that suggest how to format ratings as ranges? Example, what's the best format for the CONDITION rating? - 0 to 5, zero is best - 0 to 5, five is best - 1 to 5, one is best - 1 to 5, five is best -------------------------