Insert Numbers Counting From 1 upwards Until It Reaches A Blank Cell Then Start Again

Hi all,

I wonder if anyone can help me I am trying to insert numbers into an excel spreadsheet that could vary in length starting from cell C5 counting from 1 to however many it gets to before it hits a blank cell in column B then it must skip the cell in column c and go to the next below is a rough example. This also should stop the routine if it gets to two blanks cells in column B as this would signify the end of the spreadsheet.

A B C
7073961 1
7073961 2

7074001 1
7074001 2
7074001 3
7074001 4
7074001 5

I have attached a sample spreadsheet as well.

If you have any questions that might aid with this then please do not hesitate to ask!


Thanks for all your help.