Calculate percentiles

[_nappi]

Hi all, I'm totally confused about a simple problem of stats. 

I have a DB where each row reports the value of sales for each individual product on each customer.

I built a pivot table because I would like to understand how many sales values fall within a certain range. Using the round of all sales values as the only dimension, how can I calculate the percentile? That is, how can I understand that that sales value falls within the 25%, 50% and 75% percentile?

Thanks in adavance

[Nicolae_Alecu]

Hello,

You can use fractile() function.

Have a nice day,

[_nappi]

It doesn't work. 

My DB is similar to:

ID_ORDER	ID_USER	ID_PRODUCT	REVENUE
1	A	X	560 €
1	A	Y	440 €

Thanks