I have a workbook where on the tab "Data"

tab "Data" Column A, Cells A2:A2500 Gives a Year Value (for example, 2007,
2008)

tab "Data" Column D, Cells D2:D2500 Gives a specific Date (for example Feb
1, 2007, Feb 18, 2007)

tab "Data" Column C, Cells C2:C2500 Subtracts the Value of the date from the
current line from the date of the line previous (=D4-D3) and returns a number
value.

tab "Data" Column G, Cells G2:G2500 gives a the department of each record.
(For example "Admin".


What I am trying to do is in cell C20 of the "Frequencies" tab, I would like
to go back and find the largest number in "Data" worksheet, cells C2:C2500,
where the year is 2007, and returns the highest value in that range.

Could anyone please give me a hand with this?

Thank you,
Gina