Run a macro to place sequential numbers at each row in a range

Hi everyone,

I am looking to add sequential numbers to a data set, however i would only want the number to increase each time a blank row was located.

eg.

Row 1 Yes 000001
Row 2 Yes 000001
Row 3 Yes 000001
Row 4
Row 5 Yes 000002
Row 6 Yes 000002

The number of rows between each gap is not predetermined.

Please see the attached example doc for the desired outcome.

Any assistance would be much appreciated. I have upwards of 500,000 rows to work through so a macro to process the data would be a GREAT advantage.

Thank you in advance.