Exhibit 99.1

Last Updated 4/25/2007

Pinnacle West Capital Corporation

Quarterly Consolidated Statistical Summary

Periods Ended March 31, 2007 and 2006

List of Contents

2007 First Quarter Summary

2006 by Quarter

2005 by Quarter

2004 by Quarter

Quarters may not sum to totals due to rounding.

Certain current and prior-year amounts have been reclassified to conform to current-period presentation.

The definitions of terms used in this statistical summary are contained
in the “Glossary of Terms” on the Pinnacle West website at:

http://www.pinnaclewest.com/files/investors/2007Q1QuarStatsGloss.pdf

This statistical data may be graphed in various quarterly or annual comparisons
using the “Interactive Charts” tool on the Pinnacle West website at:

http://www.pinnaclewest.com/main/pnw/investors/financials/quarterly/landing.html