YEAR,Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec,Annual 24-hr Avg. 1990,3211,3441,3673,3784,3744,3800,3745,4177,3852,3518,3355,3171,3623 1991,3107,3394,3617,3719,3803,3823,3886,4289,3923,3703,3501,3610,3700 1992,3385,3593,3869,3990,3997,3927,3938,4322,4100,3795,3509,3590,3846 1993,3255,3458,3810,4067,4052,4022,3926,4361,4208,3876,3661,3729,3871 1994,3539,3673,4057,4401,4141,4208,4134,4251,4258,3921,3602,3719,3993 1995,3467,3685,3815,4037,4147,4064,4222,4277,4258,4041,3854,3944,3984 1996,3474,3833,4056,4129,4044,3896,3969,4460,4216,3926,3843,3773,3968 1997,3646,3832,3951,4169,4328,4526,4139,4496,4165,3886,3734,3838,4059 1998,3547,3752,3963,4147,4147,4131,4176,4501,4313,4128,3940,4036,4065 1999,3779,4021,4316,4490,4693,4824,4648,4616,4359,4284,4093,4249,4364 2000,3784,4036,4185,4207,4316,4442,4032,,4594,4226,3776,4248 2001,3863,4065,4195,4346,4365,4347,4285,4667,4394,4205,4516,4225,4289 2002,4110,3996,4369,4724,4531,4687,4496,4734,4545,4522,4121,4233,4422 2003,3964,4098,4195,4471,4543,4612,4409,4724,4427,4322,4071,4099,4328 2004,3836,4061,4237,4401,4367,4378,4621,4722,4419,4311,4155,4389,4325 2005,4046,4206,4293,4433,4560,4615,4713,4802,4493,4237,4229,4352,4415 2006,4076,4260,4307,4496,4569,4590,3708,3670,3716,4005,4131,4161,4141 2007,3925,4140,4270,4358,4480,4214,4201,4491,4130,4073,3958,4127,4197 2008,3863,4045,4095,4305,4414,4288,4353,4553,,4237,3984,4210 2009,3944,4077,4149,4501,4688,4454,4633,4792,4548,4470,4125,4369,4396 2010,4004,4212,4625,4610,4179,4659,4791,5214,4603,4358,4109,4457,4485 2011,4155,4261,4603,4612,4799,4916,4793,4937,4717,4586