my $EngWales_First_cat_observed;
  my $EngWales_First_cat_DSRs;
  my $EngWales_First_cat_Lower_95_Confidence_Limits;
  my $EngWales_First_cat_Upper_95_Confidence_Limits;
  
  my $EngWales_Second_cat_observed;
  my $EngWales_Second_cat_DSRs;
  my $EngWales_Second_cat_Lower_95_Confidence_Limits;
  my $EngWales_Second_cat_Upper_95_Confidence_Limits;
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Actually, ultimately, I suggest that you create a Cat object with certain attributes. Then you just need an array of these Cat objects. So, after mastering perldsc, read perltoot or by TheDamian's masterwork on the subject "Object-Oriented Perl"