Question : cumulative sums

Hello, I have a table in oracle 10.2 with the following structure:
tt_balance_acum(
  cod_empresa number not  null enable,
  cod_oficina number not  null enable,
  cod_cuenta varchar2(  32 byte ) not null enable,
  fec_corte date,
  fec_fin_mes date,  
  fec_fin_año date,
  saldo number( 19, 2 ) default 0 )
this is a sample data:
1      255      1000000000      01-JAN-2005      31-JAN-2005      31-DEC-2005      24377161.83
1      255      1000000000      03-JAN-2005      31-JAN-2005      31-DEC-2005      24473060.42
1      255      1000000000      04-JAN-2005      31-JAN-2005      31-DEC-2005      24663020.54
1      255      1000000000      05-JAN-2005      31-JAN-2005      31-DEC-2005      24622068.1
1      255      1000000000      06-JAN-2005      31-JAN-2005      31-DEC-2005      24623397.32
1      255      1000000000      01-FEB-2005      28-FEB-2005      31-DEC-2005      24627780.39
1      255      1000000000      02-FEB-2005      28-FEB-2005      31-DEC-2005      24851049.34
1      255      1000000000      03-FEB-2005      28-FEB-2005      31-DEC-2005      24701121.18
1      255      1000000000      04-FEB-2005      28-FEB-2005      31-DEC-2005      24878186.19
1      255      1000000000      09-FEB-2005      28-FEB-2005      31-DEC-2005      24700391.67
1      255      1000000000      10-FEB-2005      28-FEB-2005      31-DEC-2005      24693361.77
1      255      1000000000      01-MAR-2005      31-MAR-2005      31-DEC-2005      25099924.36
1      255      1000000000      02-MAR-2005      31-MAR-2005      31-DEC-2005      25344461.78
1      255      1000000000      03-MAR-2005      31-MAR-2005      31-DEC-2005      25229635.86
1      255      1000000000      04-MAR-2005      31-MAR-2005      31-DEC-2005      25148029.08
1      255      1000000000      07-MAR-2005      31-MAR-2005      31-DEC-2005      25206505.98
1      255      1000000000      08-MAR-2005      31-MAR-2005      31-DEC-2005      25257520.6

I need to calculate the accrued for the column "saldo", for the previous date, for the current month, for the previous month, for the current quarter, for the previous quarter for the current year and the previous year

Answer : cumulative sums

Can you find the group using ADSIedit?