イラストレーター GeometricBoundsって何だ?

    Public Function WhatIsGeometricBounds()
        Dim IllApp As New Illustrator.Application
        Dim IllDoc As Illustrator.Document
        Dim pItem As PathItem
        Dim temObj As Object

        IllDoc = IllApp.ActiveDocument

        For Each pItem In IllDoc.Selection
            Console.WriteLine("top: " & pItem.Top)
            Console.WriteLine("left: " & pItem.Left)
            Console.WriteLine("height: " & pItem.Height)
            Console.WriteLine("width: " & pItem.Width)
            Console.WriteLine("bottom: " & pItem.Top - pItem.Height)
            Console.WriteLine("right: " & pItem.Width + pItem.Left)

            temObj = pItem.GeometricBounds
            For n As Integer = 0 To 3
                Console.WriteLine("GeometricBounds(" & n & "): " & temObj(n))
            Next
        Next

        Return temObj
    End Function

        '結果・・・とある四角形です

        'top: 521.3896
        'left: 198.5
        'height: 138
        'width: 236
        'bottom: 383.3896
        'right: 434.5
        'GeometricBounds(0): 199
        'GeometricBounds(1): 520.8896484375
        'GeometricBounds(2): 435
        'GeometricBounds(3): 382.8896484375

        '・・・ということは

        'GeometricBounds(0) : Left
        'GeometricBounds(1) : top
        'GeometricBounds(2) : Right
        'GeometricBounds(3) : bottom

        'てな感じでよござんしょか?
        'しかしレフトとライトの数値が丸まってるのとトップとボトムの小数点以下が同じなのが気になる。
        '何でだ????