Highest mean monthly level, Lake Michigan, 1860-1955
#Lake Michigan-Huron, highest monthly mean level for each calendar year,
#1860-1955.  (Add 500 to get height in feet above sea level.)
83.3    83.5    83.2    82.6    82.2    82.1    81.7    82.2    81.6    82.1
82.7    82.8    81.5    82.2    82.3    82.1    83.6    82.7    82.5    81.5
82.1    82.2    82.6    83.3    83.1    83.3    83.7    82.9    82.3    81.8
81.6    80.9    81.0    81.3    81.4    80.2    80.0    80.85   80.83   81.1
80.7    81.1    80.83   80.82   81.5    81.6    81.5    81.6    81.8    81.1
80.5    80.0    80.7    81.3    80.7    80.0    81.1    81.87   81.91   81.3
81.0    80.5    80.6    79.8    79.6    78.49   78.49   79.6    80.6    82.3
81.2    79.1    78.6    78.7    78.0    78.6    78.7    78.6    79.7    80.0
79.3    79.0    80.2    81.5    80.8    81.00   80.96   81.1    80.8    79.7
80.0    81.6    82.7    82.1    81.7    81.5