Hi, I have a table containing grade levels K-5 with 5 different years as col/row headers and retention % as data fields. I want to track the K class through the 5 years and see what the probability is that a student went through all 5 years without being retained. We can assume that the class sizes remain constant for each year. Right now here are the datapoints I am looking at.....

Kinder 2001-02 4.7%

1st 2002-03 11.6%

2nd 2003-04 5.6%

3rd 2004-05 19.8%

4th 2005-06 11.9%

What are the chances a student went through all those years without being retained? I have tried a few things but am not confident with the resulting numbers...(~56%).

Thanks for any help you can provide!