I don't have SET data, but here are the Friday closes.
Third Friday to third Friday changes (at Close) for SPX
Start 19980320 Price: 1,099.16
19980417, 1,122.72, %Chg: 2.14
19980515, 1,108.73, %Chg: -1.25
19980619, 1,100.65, %Chg: -0.73
19980717, 1,186.75...