If there are 250 snails in a pond, and within a year their number increases to 2500 by reproduction. What should be their birth rate per snail per year?

The initial number of snails is 250, and the final number of snails after reproduction is 2500.
Total number of new snails = Final number of snails - Initial number of snails
Total number of new snails = 2500 - 250
Total number of new snails = 2250
Birth rate per snail per year = Total number Of new snails / Initial number of snails
Birth rate per snail per year = 2250 / 250
Birth rate per snail per year = 9