Multiply By Loops

Nested Loop  (cost=0.29..3812.44 rows=48 width=36)
             (actual time=0.041..18.902 rows=48.00 loops=1)
  ->  Seq Scan on customers c  (cost=0.00..214.00 rows=12 width=12)
                               (actual time=0.018..2.104 rows=12.00 loops=1)
        Filter: (region = 'nordics'::text)
        Rows Removed by Filter: 9988
  ->  Index Scan using orders_customer_id_idx on orders o
        (cost=0.29..299.30 rows=4 width=28)
        (actual time=0.203..1.396 rows=4.00 loops=12)
        Index Cond: (customer_id = c.id)
Planning Time: 0.211 ms
Execution Time: 19.104 ms

Roughly how much of the 19.1 ms was spent inside the index scan on orders?