In reply to tim.

Gift Exchange: 4 Pairs of Spouses + 1 Extra
P1 SP1 P2 SP2 P3 SP3 P4
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Year 1 SP3 P3 P4 P1 SP2 SP1 P2
Year 2 P3 P4 SP1 P1 SP2 P2 SP3
Year 3 SP3 P2 SP1 P3 P4 P1 SP2
Year 4 SP2 P2 P3 SP3 P1 P4 SP1
Year 5 SP3 P2 P4 P3 P1 SP2 SP1
Year 6 P3 P2 P1 SP3 P4 SP2 SP1
Year 7 SP3 P4 P3 SP1 P1 SP2 P2
Year 8 P3 P2 SP3 P4 SP2 SP1 P1
Year 9 P3 P2 P1 SP3 P4 SP1 SP2
Year 10 SP2 P3 P4 SP3 P2 SP1 P1