Belady's Extra Frame

Reference string, in order:

1, 2, 3, 4, 1, 2, 5, 1, 2, 3, 4, 5

With 3 frames under FIFO, the trace is:

#	ref	result	evict	frames (oldest first)
1	1	fault	-	1
2	2	fault	-	1, 2
3	3	fault	-	1, 2, 3
4	4	fault	1	2, 3, 4
5	1	fault	2	3, 4, 1
6	2	fault	3	4, 1, 2
7	5	fault	4	1, 2, 5
8	1	hit	-	1, 2, 5
9	2	hit	-	1, 2, 5
10	3	fault	1	2, 5, 3
11	4	fault	2	5, 3, 4
12	5	hit	-	5, 3, 4

That is 9 faults. Run the same string under FIFO with 4 frames. How many faults?