These data come from Tuttle Creek Reservior (Corp of Engineers). Values are
monthly totals of actual pan water evaporation, based on daily measurements.
The format for the data file is:

Year   month    total evaporation for the month (inches)
---------------------data follows-----------------------------
80 4 5.35
80 5 6.65
80 6 9.39
80 7 14.23
80 8 10.95
80 9 7.26
80 10 4.83
81 4 7.32
81 5 6.29
81 6 8.4
81 7 7.57
81 8 7.09
81 9 6.14
81 10 2.77
82 4 6.14
82 5 6.53
82 6 6.25
82 7 9.3
82 8 6.61
82 9 5.22
82 10 4.27
83 4 4.14
83 5 6.59
83 6 6.74
83 7 11.98
83 8 10.11
83 9 8.29
83 10 3.59
84 4 4.74
84 5 6.03
84 6 8.51
84 7 10.26
84 8 9.22
84 9 7.17
84 10 2.52
85 4 5.37
85 5 7.75
85 6 7.09
85 7 9.3
85 8 6.07
85 9 5.3
85 10 3.11
86 4 5.90
86 5 6.32
86 6 7.94
86 7 9.60
86 8 5.96
86 9 4.86
86 10 2.41
87 4 6.64
87 5 6.78
87 6 8.68
87 7 10.45
87 8 8.00
87 9 6.72
87 10 4.46
88 4 6.54
88 5 9.16
88 6 11.71
88 7 8.90
88 8 9.42
88 9 7.18
88 10 3.77
89 4 7.37
89 5 7.63
89 6 7.67
89 7 8.92
89 8 7.49
89 9 4.63
89 10 4.72
90 4 4.74
90 5 5.07
90 6 8.42
90 7 9.72
90 8 7.79
90 9 6.25
90 10 5.17
91 4 5.23
91 5 5.50
91 6 8.77
91 7 11.59
91 8 8.73
91 9 7.14
91 10 5.26
92 4 4.41
92 5 7.26
92 6 5.30
92 7 7.11
92 8 6.88
92 9 7.00
92 10 3.59
93 4 3.92
93 5 5.02
93 6 6.32
93 7 6.22
93 8 7.13
93 9 4.69
93 10 4.09
94 4 5.63
94 5 7.24
94 6 8.27
94 7 8.19
94 8 8.90
94 9 5.85
95 4 4.42
95 5 4.48
95 6 7.13
95 7 7.75
95 8 8.94
95 9 4.90
95 10 4.59
96 4 7.18
96 5 5.83
96 6 7.92
96 7 8.19
96 8 6.14
96 9 5.05
96 10 4.68
97 4 4.08
97 5 6.94
97 6 7.75
97 7 10.27
97 8 7.51
97 9 5.63
97 10 4.17
98 4 4.89
98 5 6.70
98 6 8.24
98 7 6.55
98 8 7.30
98 9 5.97
98 10 3.68
99 4 4.44
99 5 6.34
99 6 5.74
99 7 10.10
99 8 7.36
99 9 5.52
99 10 3.44
00 4 4.31
00 5 6.40
00 6 9.39
00 7 8.64
00 8 6.70
00 9 9.66
00 10 3.98
01 4 6.06
01 5 7.62
01 6 8.44
01 7 10.08
01 8 8.82
01 9 5.84
01 10 4.35
02 4 6.12
02 5 6.17
02 6 10.07
02 7 11.32
02 8 8.37
02 9 5.95
02 10 2.74
03 4 5.90
03 5 5.89
03 6 6.80
03 7 10.07
03 8 9.09
03 9 6.06 
03 10 3.25