年

  2003

  2004

  2005

  2006

  2007

1月

4,343,648

4,300,796

4,205,348

4,202,072

4,216,333

2月

4,336,577

4,296,549

4,204,477

4,202,495

4,215,728

3月

4,325,647

4,283,474

4,199,962

4,196,938

4,246,889

4月

4,317,155

4,282,836

4,200,417

4,198,044

4,245,870

5月

4,324,112

4,287,223

4,200,370

4,201,709

4,250,470

6月

4,325,116

4,284,444

4,201,247

4,215,338

4,231,002

7月

4,324,829

4,286,584

4,203,040

4,213,841

4,227,004

8月

4,326,761

4,261,959

4,202,842

4,212,743

4,229,371

9月

4,328,035

4,253,905

4,204,726

4,215,370

4,233,352

10月

4,326,501

4,245,979

4,206,218

4,216,968

4,238,254

11月

4,303,488

4,234,821

4,209,135

4,215,859

4,238,181

12月

4,303,153

4,201,124

4,200,014

4,210,950

4,234,216

单位：百万立方英尺