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  CUSIP NO. 989070107                 13G
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      NAME OF REPORTING PERSON
 1    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

      Bank of America National Trust and Savings Association
      94-1687665
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      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
 2                                                              (a) [X]
                                                                (b) [_]
                                                 
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      SEC USE ONLY
 3
 

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      CITIZENSHIP OR PLACE OF ORGANIZATION
 4    
      United States of America

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                          SOLE VOTING POWER
                     5
     NUMBER OF            None
 
      SHARES       -----------------------------------------------------------
                          SHARED VOTING POWER
   BENEFICIALLY      6
                          8,051,427
     OWNED BY
                   -----------------------------------------------------------
       EACH               SOLE DISPOSITIVE POWER
                     7   
    REPORTING             None
 
      PERSON       -----------------------------------------------------------
                          SHARED DISPOSITIVE POWER
       WITH          8
                          8,051,427
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      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 9          
      8,051,427

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      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
10                  
      
 
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      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9
11   
      5.6%
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      TYPE OF REPORTING PERSON*
12
      BK

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                     *SEE INSTRUCTION BEFORE FILLING OUT!

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