how to calculate expression based on month?

[#1]

Hi,

i have attached qv file and excel data source below.

i nee to show in straight chart expression part like

if i select 2014 then (count of emp in Jan*value for 2014 jan+count of emp in feb*value for 2014 feb+count of emp in feb*value for 2014 feb......like YTD Basis)

if i select 2013 also i need to show same as above YTD basis.

Can you please send me the solution for below attached file?