Aggregate Formula: Calculate Conversion Rate based on Orders and Sessions: Parameter EXPR not correct

Aggregate Formula: Calculate Conversion Rate based on Orders and Sessions: Parameter EXPR not correct

Dear Zoho Reports Community,

I have following table:

Date | Type | Value

with Order and Sessions information, e.g.:

Date Type Value
30 Nov 2017 Orders 10
30 Nov 2017 Sessions 100
31 Nov 2017 Orders 5
31 Nov 2017 Sessions 100
... ... ...

Now I want to calculate the conversion rate for each day, based on Orders/Sessions. This would lead to a conversionrate of 10% for 30 Nov 2017 and 5% for 31 Nov 2017

At the end, I want to have a chart, showing the conversion per day. So I added a Aggregate formula in the chart with this code:
  1. SUMIF("GoogleData"."Type"='Orders',"Value",0)/SUMIF("GoogleData"."Type"='Sessions',"Value",0)

However, when I click okay, I always get the error message "...Parameter EXPR not correct..."
What does it mean, and what can I do to solve it?

Best,
Fabian