ZERO Sorts between One and Two instead of before One "1, 0, 2, 3, 4"

ZERO Sorts between One and Two instead of before One "1, 0, 2, 3, 4"

We use numbers in our Task "Priority" field from 0-9.  0 is our highest priority while 9 is the lowest.

When we sort our task list by ascending order, the list shows priority 1 before priority 0, followed by priority 2, 3, and so forth. 

Please fix the system so that a zero value is a lower value than one.

Currently: 1, 0, 2
Should be: 0, 1, 2


Thanks.