|                                                                               |   |                    |    | Twelve       |   |  Three  |   |
|------------------------------------------------------------------------------------|--------|-------------------------|---------|--------------|--------|--------------|--------|
|                                                                               |   |                    |    |  Months |   |  Months |   |
|                                                                               |   | Year Ended December 31, |    |  Ended  |   |  Ended  |   |
|                                                                               |   | 2005                    |    | 2006         |   | 2007         |   | 2008 |   |   | 2009 |   |  3/31/2010 |   |  3/31/2010 |   |
|  EARNINGS                                                                     |   |               |    |    |   |    |   |    |   |   |   |   |   |   |   |   |   |   |
| Income Before Income Taxes and Equity Earnings                                |   | $                       | 114,341 |         | $      | 138,289      |   | $ | 87,333 |   | $ | 129,489 |   | $ | 140,035 |   | $ |  165,002 |   | $ |  40,520 |   |
| Fixed Charges (as below)                                                           |   |                    | 55,808  |         |   | 63,242       |   |   | 79,435 |   |   | 119,516 |   |   | 109,146 |   |   |  112,378 |   |   |  29,319 |   |
| Total Earnings                                                                     |   | $                       | 170,149 |         | $      | 201,531      |   | $ | 166,768 |   | $ | 249,005 |   | $  | 249,181 |   | $ |  277,380 |   | $ |  69,839 |   |
|                                                                               |   |                    |    |         |   |         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| FIXED CHARGES                                                                      |   |                    |    |         |   |         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Interest Expense                                                                   |   | $                       | 50,089  |         | $      | 55,213       |   | $ | 60,619 |   | $ | 93,150 |   | $  | 70,500 |   |   |  72,745 |   | $ |  18,544 |   |
| Credit for Allowance for Borrowed Funds    Used During Construction |   |                    | 1,198   |         |   | 2,208        |   |   | 9,795 |   |   | 19,800 |   |   | 29,546 |   |   |  30,533 |   |   |  8,500 |   |
| Trust Dividends                                                                    |   |                    | (179    | )            |   | (179         | )      |   | (179 | ) |   | (134 | )  |   | - |   |   |  - |   |   |  - |   |
| Estimated Interest Element in Lease Rentals                                        |   |                    | 4,700   |         |   | 6,000        |   |   | 9,200 |   |   | 6,700 |   |   | 9,100 |   |   |  9,100 |   |   |  2,275 |   |
| Total Fixed Charges                                                                |   | $                       | 55,808  |         | $      | 63,242       |   | $ | 79,435 |   | $ | 119,516 |   | $  | 109,146 |   | $ |  112,378 |   | $ |  29,319 |   |
|                                                                               |   |                    |    |         |   |         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Ratio of Earnings to Fixed Charges                                                 |   |                    | 3.04    |         |   | 3.18         |   |   | 2.09 |   |   | 2.08 |   |   | 2.28 |   |   |  2.46 |   |   |  2.38 |   |