error un calc avg in graph

[dcd123456]

hello

i have a table with 3 fields Month, date1 and date2. I need to show a bar chart  agregated by month that show the avg of days between two date fields.

In dimension i define the field month, in expresion i put the next expresion:

num(avg(H_MFECHA-H_MFECHA2),'####,##',',','.')

the result of the avg in the bar chart are wrong.

somebody know what is wrong??

[dcd123456]

it works ok

thanks

regards

diego