with t(id, val) as
(
select 1, 180 from dual
union all select 2, 190 from dual
union all select 3, 200 from dual
union all select 4, 180 from dual
union all select 5, 170 from dual
union all select 6, 220 from dual
union all select 7, 300 from dual
union all select 8, 330 from dual
union all select 8.1, 290 from dual
union all select 8.2, 260 from dual
union all select 9, 150 from dual
union all select 10, 140 from dual
union all select 12, 120 from dual
union all select 12, 100 from dual
)
select id, val, lag(mn, 1, 1) over (order by id) grp
from t
match_recognize
(
  order by id
  measures match_number() mn
  all rows per match
  pattern (strt x*)
  define x as max(val) * 1.15 >= next(val) and next(val) >= min(val) * 0.85
);

        ID        VAL        GRP
---------- ---------- ----------
         1        180          1
         2        190          1
         3        200          1
         4        180          1
         5        170          1
         6        220          1
         7        300          2
         8        330          2
       8.1        290          2
       8.2        260          2
         9        150          3
        10        140          3
        12        120          3
        12        100          4

14 rows selected.

with t(id, val) as
(
select 1, 180 from dual
union all select 2, 290 from dual
union all select 3, 200 from dual
union all select 4, 180 from dual
union all select 5, 170 from dual
union all select 6, 220 from dual
union all select 7, 300 from dual
union all select 8, 330 from dual
union all select 8.1, 290 from dual
union all select 8.2, 260 from dual
union all select 9, 150 from dual
union all select 10, 140 from dual
union all select 11, 120 from dual
union all select 12, 100 from dual
)
select id, val, mn grp
from (select t.*, lag(val) over (order by id) vv from t) t
match_recognize
(
  order by id
  measures match_number() mn
  all rows per match
  pattern (strt x*)
  define x as max(x.vv) * 1.15 >= next(x.vv) and next(x.vv) >= min(x.vv) * 0.85
);