excel - Approximate match within a sub-array -

i have table following:

name   quota-date   quota ami     5/1/2010    75000 ami     1/1/2012    100000 ami     6/1/2014    150000 john    8/1/2014    0 john    4/1/2015    50000 rick    5/1/2011    100000 

(dates shown in american format: m/d/yyyy). "quota date" first month of active new "quota" next it. e.g. ami's quota 75000 each month between may 2010 , december 2011.

i need formula fetch quota of given person , given month: active quota of person in every month. needed formula calculate third column of table:

name    month       quota ami     6/1/2010    75000 ami     12/1/2011   75000 ami     1/1/2012    100000 ami     7/1/2014    150000 john    10/1/2014   0 john    4/1/2015    50000 

i prefer not maintain first table sorted, if make things simpler, would.

what correct formula "quota" on second table?

if new data in columns a-c , original data columns a-c in sheet1, enter formula in b2:

=sumifs(sheet1!c:c,sheet1!a:a,a2,sheet1!b:b,max(if((sheet1!a:a=a2)*(sheet1!b:b<=b2),sheet1!b:b,"")))

this formula works if have numbers in 3rd column, more complicated make working on text too.