Here is a good start. I'm doing something wrong with the ReDim's because the total count is 5 off. But as I'm out of time, I figured I would post what I had...Maybe someone else can spot the flaw.

 Code:
Dim $recent[],$1years[],$2years[],$3years[],$4years[],$older[]
$today = SerialDate(@Date)
$dir = "C:\Windows"
$files = DirList($dir,2)

For Each $file in $files
   $moddate = GetFileTime($file)
   $sermod = SerialDate($moddate)
   If ($today-$sermod) < 365
      ReDim Preserve $recent[1+ubound($recent)]
      $recent[ubound($recent)] = $file
   Else
      If ($today-$sermod) < 730
         ReDim Preserve $1years[1+ubound($1years)]
         $1years[ubound($1years)] = $file
      Else
         If ($today-$sermod) < 1095
            ReDim Preserve $2years[1+ubound($2years)]
            $2years[ubound($2years)] = $file
         Else
            If ($today-$sermod) < 1460
               ReDim Preserve $3years[1+ubound($3years)]
               $3years[ubound($3years)] = $file
            Else
               If ($today-$sermod) < 1825
                  ReDim Preserve $4years[1+ubound($4years)]
                  $4years[ubound($4years)] = $file
               Else
                  ReDim Preserve $older[1+ubound($older)]
                  $older[ubound($older)] = $file 
               Endif
            Endif
         Endif
      Endif
   Endif
Next

? "Total Files: "+UBound($files)
? "Files Under 1 Year  : "+UBound($recent)
? "Files Under 2 Years : "+UBound($1years)
? "Files Under 3 Years : "+UBound($2years)
? "Files Under 4 Years : "+UBound($3years)
? "Files Under 5 Years : "+UBound($4years)
? "Files Over  5 Years : "+UBound($older)

get $

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;  SerialDate() - Converts date to a numerical value. Used for date calculations.    ;;;
;;;  Written By: Jens Meyer                                                            ;;;
;;;  http://www.kixtart.org/forums/ubbthreads.php?ubb=showflat&Board=7&Number=82574    ;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
Function serialdate($ExpD)
  Dim $z,$h,$a,$b,$c,$y,$m,$d
  If InStr($ExpD,'/')
    $ExpD=Split($ExpD,'/')
    $y=Val($ExpD[0])
    $m=Val($ExpD[1])
    $d=Val($ExpD[2])
    If $m<3
      $m=$m+12
      $y=$y-1
    EndIf
    $SerialDate=$d+(153*$m-457)/5+365*$y+$y/4-$y/100+$y/400-306
  Else
    $z=0+$ExpD+306
    $h=100*$z-25
    $a=$h/3652425
    $b=$a-$a/4
    $y=(100*$b+$h)/36525
    $c=$b+$z-365*$y-$y/4
    $m=(5*$c+456)/153
    $d=$c-(153*$m-457)/5
    If $m>12
      $y=$y+1
      $m=$m-12
    EndIf
    $SerialDate=Right('0000'+$y,4)+'/'+Right('00'+$m,2)+'/'+Right('00'+$d,2)
  EndIf
EndFunction

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;  DirList() - Enumerates the files in a directory into an array.                    ;;;
;;;  Written By: Jens Meyer                                                            ;;;
;;;  http://www.kixtart.org/forums/ubbthreads.php?ubb=showflat&Board=7&Number=82581    ;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
Function dirlist($dirname, optional $options)
  dim $filename, $counter, $filepath, $mask
  dim $list, $sublist, $subcounter
  $counter=-1
  $dirname=trim($dirname)
  if $dirname=''
    $dirname=@CURDIR
  endif
  if right($dirname,1)='\'
    $dirname=left($dirname,len($dirname)-1)
  endif
  if getfileattr($dirname) & 16
    $mask='*.*'
  else
    $mask=substr($dirname,instrrev($dirname,'\')+1)
    $dirname=left($dirname,len($dirname)-len($mask)-1)
  endif
  redim $list[10]
  $filename=dir($dirname+'\'+$mask)
  while $filename<>'' and @ERROR=0
    if $filename<>'.' and $filename<>'..'
      select
      case (getfileattr($dirname+'\'+$filename) & 16)
        if $options & 1
          $counter=$counter+1
          if $options & 2
            $list[$counter]=$dirname+'\'+$filename+'\'
          else
            $list[$counter]=$filename+'\'
          endif
        endif
        if ($options & 4)
          $sublist=dirlist($dirname+'\'+$filename+'\'+$mask,$options)
          if ubound($sublist)+1
            redim preserve $list[ubound($list)+ubound($sublist)+1]
            for $subcounter=0 to ubound($sublist)
              $counter=$counter+1
              if $options & 2
                $list[$counter]=$dirname+'\'+$filename+'\'+$sublist[$subcounter]
              else
                $list[$counter]=$filename+'\'+$sublist[$subcounter]
              endif
            next
          endif
        endif
      case ($options & 2)
        $counter=$counter+1
        $list[$counter]=$dirname+'\'+$filename
      case 1
        $counter=$counter+1
        $list[$counter]=$filename
      endselect
      if $counter mod 10
        redim preserve $list[$counter+10]
      endif
    endif
    $filename = dir('')
  loop
  if $counter+1
    redim preserve $list[$counter]
  else
    $list=''
  endif
  if $mask<>'*.*' and ($options & 4)
    $filename=dir($dirname+'\*.*')
    while $filename<>'' and @ERROR=0
      if $filename<>'.' and $filename<>'..'
        if (getfileattr($dirname+'\'+$filename) & 16)
          $sublist=dirlist($dirname+'\'+$filename+'\'+$mask,4)
          if ubound($sublist)+1
            redim preserve $list[ubound($list)+ubound($sublist)+1]
            for $subcounter=0 to ubound($sublist)
              $counter=$counter+1
              if $options & 2
                $list[$counter]=$dirname+'\'+$filename+'\'+$sublist[$subcounter]
              else
                $list[$counter]=$filename+'\'+$sublist[$subcounter]
              endif
            next
          endif
        endif
      endif
      $filename = dir('')
    loop
  endif
  if $counter+1
    redim preserve $list[$counter]
  else
    $list=''
  endif
  $dirlist=$list
endfunction