with services as (
   select 1 id_service, 1 id_contract, to_date('01.01.2019', 'dd.mm.yyyy') date_start, to_date(null) date_stop from dual union all
   select 2, 1, to_date('01.02.2019', 'dd.mm.yyyy'), to_date('01.03.2019', 'dd.mm.yyyy') from dual union all
   select 3, 1, to_date('01.02.2017', 'dd.mm.yyyy'), to_date('01.03.2019', 'dd.mm.yyyy') from dual union all
   select 4, 2, to_date('01.11.2018', 'dd.mm.yyyy'), to_date('01.05.2019', 'dd.mm.yyyy') from dual union all
   select 5, 2, to_date('05.03.2017', 'dd.mm.yyyy'), to_date(null) from dual union all
   select 6, 2, to_date('01.02.2018', 'dd.mm.yyyy'), to_date('31.12.2018', 'dd.mm.yyyy') from dual union all
   select 7, 3, to_date('01.02.2018', 'dd.mm.yyyy'), to_date('31.12.2018', 'dd.mm.yyyy') from dual union all
   select 8, 3, to_date('01.01.2018', 'dd.mm.yyyy'), to_date('31.12.2018', 'dd.mm.yyyy') from dual union all
   select 9, 3, to_date('01.01.2018', 'dd.mm.yyyy'), to_date('01.03.2017', 'dd.mm.yyyy') from dual
)
select * from services