Create the data set. STOCKS contains yearly highs and lows for the Dow Jones Industrial Average and the dates of the high and low values each year.

data stocks;
   input year high low @@;

   datalines;
1956  521.05  462.35 1957  520.77  419.79
1958  583.65  436.89 1959  679.36  574.46
1960  685.47  568.05 1961  734.91  610.25
1962  726.01  535.76 1963  767.21  646.79
1964  891.71  768.08 1965  969.26  840.59
1966  995.15  744.32 1967  943.08  786.41
1968  985.21  825.13 1969  968.85  769.93
1970  842.00  631.16 1971  950.82  797.97
1972 1036.27  889.15 1973 1051.70  788.31
1974  891.66  577.60 1975  881.81  632.04
1976 1014.79  858.71 1977  999.75  800.85
1978  907.74  742.12 1979  897.61  796.67
1980 1000.17  759.13 1981 1024.05  824.01
1982 1070.55  776.92 1983 1287.20 1027.04
1984 1286.64 1086.57 1985 1553.10 1184.96
1986 1955.57 1502.29 1987 2722.42 1738.74
1988 2183.50 1879.14 1989 2791.41 2144.64
1990 2999.75 2365.10 1991 3168.83 2470.30
1992 3413.21 3136.58 1993 3794.33 3241.95
1994 3978.36 3593.35 1995 5216.47 3832.08
;