A group of investors was polled each week for the last five weeks about whether they were bullish or bearish concerning the market. Construct the market sentiment index for each week based on these polls. (Round your answer to 4 decimal places.)

Week	Bulls	Bears
1	62	71
2	53	72
3	51	78
4	58	75
5	31	60

	MSI
1
2
3
4
5