Spreadsheet aggregation/manipulation - excel

Question

I have a spreadsheet structured like
2005 Alameda total HS graduates 1234
2005 Alameda UC enrollees 112
2006 Alameda total HS graduates 892
2006 Alameda UC enrollees 84
...
2009 Yolo total HS graduates 1300
2009 Yolo UC enrollees 93
and so on for every CA county for several years.
I want to generate a spreadsheet like this:
county 2005 2006 ...
Alameda 11.1% 9%
Alpine 7% 8%
...
Yolo 5.5% 4%
i.e. I want to project the years from rows to columns and have a row for each county, then divide the number of graduates (the data from each odd-numbered row in the original sheet) by the number of UC enrollees (even-row data) for each year, and insert it in the appropriate cell.
This would be easy enough for me to do in Java, but I want to get a feel for what's possible just using excel/Google sheets alone - how might I go about accomplishing this?

Answer 1

Assuming the counties are sorted, and they start in cell B2, enter =B2 in cell F2, and enter the following in F3:
=INDIRECT("B"&COUNTIF(B3:B$9999,"<="&F2)+ROW())
You can change 9999 based on the number of records, but it's fine as-is.
Copy F3 down as many rows as are needed:
You can then calculate percentages using SUMPRODUCT:
=IFERROR(
SUMPRODUCT(($A$2:$A$100=G$1)*
($B$2:$B$100=$F2)*
($C$2:$C$100="UC enrollees")*
$D$2:$D$100
)
/
SUMPRODUCT(($A$2:$A$100=G$1)*
($B$2:$B$100=$F2)*
($C$2:$C$100="total HS graduates")*
$D$2:$D$100
),
"")
The first SUMPRODUCT totals UC enrollees that match the year and county. The second SUMPRODUCT does the same for HS graduates. The results are divided, and IFERROR handles divide-by-zero errors for missing data.
Since your example shows percentages, I assume you want to divide UC enrollees by HS graduates, and not the other way around. Either way, I don't get the same totals as you, so let me know if I misunderstood.

Answer 2

Here is the pivot table way of doing it for comparison.
They are many ways of doing this but I've added column headers and chosen to use this formula to put percentages in even rows of column E and zeroes in odd rows in sheet 1:-
=IF(ISEVEN(ROW()),D3/D2*100,0)
Then I've inserted a pivot table in sheet 2 referring to my data in sheet 1 and set up the fields as shown and it's pretty automatic:-