Oracle で条件に基づいて累積合計をリセットするにはどうすればよいですか?

with test_data (sort_col, addend) as
(
  SELECT 'A', 3 FROM DUAL UNION ALL
  SELECT 'B', 7 FROM DUAL UNION ALL
  SELECT 'C', 6 FROM DUAL UNION ALL
  SELECT 'D', 5 FROM DUAL UNION ALL
  SELECT 'E', 9 FROM DUAL UNION ALL
  SELECT 'F', 3 FROM DUAL UNION ALL
  SELECT 'G', 8 FROM DUAL
),
sorted_inputs (sort_col, sort_order, addend, running_sum_max_15) as
(
  SELECT sort_col, row_number() over (order by sort_col) sort_order, addend, 0 from test_data
)
SELECT sort_col, addend, running_sum_max_15
from sorted_inputs
model 
dimension by (sort_order)
measures (sort_col, addend, running_sum_max_15)
rules update
(
  running_sum_max_15[1] = addend[1],
  running_sum_max_15[sort_order>1] = 
    case 
      when running_sum_max_15[CV(sort_order)-1] < 15 
      THEN running_sum_max_15[CV(sort_order)-1] 
      ELSE 0 END + addend[CV(sort_order)]
)