c:\@Work\Perl\monks>perl -wMstrict -MData::Dump -le
"my $x = 'CA006139520,\"WINDSOR RIVERSIDE, ON CA\",2018-01-02,10';
 ;;
 my @windsordigits;
 @windsordigits = $x =~ /WINDSOR\sRIVERSIDE.*(\d\d?)/;
 dd \@windsordigits;
"
[0]

##</code><code>##

c:\@Work\Perl\monks>perl -wMstrict -MData::Dump -le
"my $x = 'CA006139520,\"WINDSOR RIVERSIDE, ON CA\",2018-01-02,10';
 ;;
 my @windsordigits;
 @windsordigits = $x =~ /WINDSOR\sRIVERSIDE.*\b(\d+)\z/;
 dd \@windsordigits;
"
[10]

##</code><code>##

@windsordigits = ...;

##</code><code>##

push @windsordigits, $x =~ /WINDSOR\sRIVERSIDE.*\b(\d+)\z/;

##</code><code>##

c:\@Work\Perl\monks>perl -wMstrict -MData::Dump -le
"my @windsordigits;
 ;;
 for my $x (
     'CA006139520,\"WINDSOR RIVERSIDE, ON CA\",2018-01-02,10',
   qq{CA006139520,\"WINDSOR RIVERSIDE, ON CA\",2018-01-02,987\n},
   qq{CA006139520,\"WINDSOR RIVERSIDE, ON CA\",2018-01-02,6\n},
   ) {
   push @windsordigits, $x =~ /WINDSOR\sRIVERSIDE.*\b(\d+)\Z/;
   }
 dd \@windsordigits;
"
[10, 987, 6]