This query is looking at the number of school lunch taken recorded for year 1 students. This is manually recorded in the census area.
To check this information go to Admin > Census > select the census to be completed > School Lunch Taken.
You should only record student who have taken a school meal on census day.
As this is just a query if this is correct for your school when you upload the Census on Collect you can annotate the reason for this.