obs date dt error 2 1974.93 -0.11412003 0.06048 3 1976.13 0.02017998 0.20736 4 1976.93 -0.28405002 0.05184 5 1977.58 -0.44069999 0.04320 6 1977.96 -0.46414001 0.02592 7 1978.23 -0.60691001 0.02592 8 1978.42 -0.56348002 0.06048 9 1978.82 -0.76762003 0.04320 10 1979.31 -0.96714002 0.02592 11 1980.10 -1.22854003 0.02592 12 1980.59 -1.45820999 0.07776 13 1980.59 -1.44239998 0.02592 14 1981.14 -1.75293997 0.01728