Define a calculation field, cG1_Stop, as IF ( G1_stop = "y" ; 1 ; 0 )
Define a summary field that specifies cG1_Stop using the "Fraction of total" option.
You can format this field as a percent when you place it on your layout.
When I use these two fields in a report, they come back as 1/100%. So perhaps the IF calculation is not counting correctly?
There are 12 records where G1_stop = "y", and 350 records total
I went back and checked a demo file I made for the fraction of total summary field concept. I'm afraid I made things too complicated here.
Just change the field to 1 so that all records return the value 1 and if you place the fraction of total summary field in a subsummary part and sort to group your records by the value of G1_Stop, you should be able to see percentages for those who answered "y".
Here's the demo file: http://www.4shared.com/file/V09WRIYL/FractionOfTotal.html
Wow, that is incredibly not intuitive, but it does work!
I'm not sure I understand the purpose of the "dummy" field, but being able to see the example of how it all works when you perform the sort helped tremendously.
Thanks so much!
Why the dummy field:
Fraction of total summaries will work with other values than just a constant '1'.
You might have values like this in a different database solution:
Value Fraction of total
The number value one is the right data type to be summed and giving all records the same value makes each individual record the same size fraction of the total.