Visual indication of trend direction
 

Hi there,
I have data series for which I calculated the growth percentage
using the _slope_ function, and it works nicely.
However, I feel that the number i get could be too daunting an
experience for my intended audience, so I would prefer to "mask" them
under just three symbols:

if the % of growth is between -1% and 1%, put "="
If the % of growth is higher than 1%, put a up-pointing arrow
else put a down-pointing arrow.

I concocted something that works, using "windings" font and a set of
"IF" statement, but it is pretty inelegant.
Does someone has any better trick to share?

Thanks in advance

Danilo