Cells auto-divide evenly

On the Worksheet 'Total Job Cost':
I'm trying to figure out a formula for B19:B29, so that if there is a name chosen in any of the cells E19:E29, then the cells B19:B29 automatically divide the number in cell C3 by how many names have been chosen in cells E19:E29. To be clear, I don't want a quotient in corresponding cells that don't have a name. So, if there's a name in E19 (and no other names in the cells E20:E29), then B19 will auto-divide the number in cell C3 by "1". If there are names in E19, E20, & E21 (and no other names in E22:E29), then B19, B20 & B21 will auto-divide cell C3 by "3".

Thanks for any help!!