[amelia] Bounds Issue

Hi, I would like to set bounds for some of my variables. For example I have a variable that measures the number of health personnel in a given province. The min should be 0, but I do not require a max bound. What would be the best approach for this type of bound? Should I be setting the max to infinity? Also, I have set a bound for one of my dependent variables that is a percentage of votes in a given province. The min is 0 and the max is 1. However, when I impute my data the min for this variable is -1.388e-17, which is nearly 0. I am not sure why this happens and if it is ok for me to keep a negative number (even though it is so small) as my dependent variable (that is a proportion). Any suggestions? Thank you for your help. Sera