OK, never mind. I spotted my own idiocy. I'd originally done it in 20°C
steps and then decided to go in 10°C (with a formula for the steps =
cell above plus 10). I'd changed the step value but forgot to change
the upper value. So I ended up with 100 - 119.9999, 109.9999 - 129.9999
etc, so I was counting everything twice

Sorry for wasting everyone's time (I had spent 1/2 an hour trying to
figure it out before posting, then just after posting noticed what I'd
done).

Cheers,

Rob


--
Rob_T
------------------------------------------------------------------------
Rob_T's Profile: http://www.excelforum.com/member.php...fo&userid=4952
View this thread: http://www.excelforum.com/showthread...hreadid=555513