Last fiscal year period

HI

I need to create a variable which will fetch me the data for last fiscal year

e.g, current month : 02.2014

it should fetch me the data for 02.2012 to 02.2013..

Any hints on how to write this logic in the customer exit?/

i can derive high value as below- but need help on how to define low value ?

WHEN 'ZPYTD'.

CLEAR: date_py.

date_py = sy-datum - 365.

l_s_range-high = date_py.

l_s_range-sign = 'I'.

l_s_range-opt = 'BT'.

APPEND l_s_range TO e_t_range.