Good Morning Purfleet

Thank you for your prompt response.

Yes that certainly seems to do what I want - I did not realise it could be so simple!

I have a subsidiary question if I may: My worksheet is set up in rows (not the tabular columns Excel seems to prefer) as this facilitated the trend chart I have created. Now the conditional formatting rules fix locations with $ so I cannot simply copy along the row but it appears I have to enter the rules for each cell. Is this correct or is there a way to copy and paste to save all that manual inputting?

Thanks