Just for fun, I agree with Greg's modifications, though changing the code to

Option Explicit

Sub Document_ContentControlOnExit(ByVal oCC As ContentControl, Cancel As Boolean)
    If oCC.Type = 3 Or oCC.Type = 4 Then
        Select Case oCC.Range.Text
            Case "Y"
                oCC.Range.Cells(1).Shading.BackgroundPatternColor = &H50B000
                oCC.Range.Font.ColorIndex = wdWhite
            Case "N"
                oCC.Range.Cells(1).Shading.BackgroundPatternColor = wdColorRed
                oCC.Range.Font.ColorIndex = wdWhite
            Case "NA"
                oCC.Range.Cells(1).Shading.BackgroundPatternColor = &HC07000
                oCC.Range.Font.ColorIndex = wdWhite
            Case Else
                oCC.Range.Cells(1).Shading.BackgroundPatternColor = wdColorAutomatic
                oCC.Range.Font.Color = &H808080
        End Select
        UpdateTotals
    End If
lbl_Exit:
    Exit Sub
End Sub
will make the selections more readable and match the colours I used in the attachment I returned earlier.
The code that updates the totals in that attachment can also be tweaked further
Option Explicit

Sub UpdateTotals()
'A basic Word macro coded by Greg Maxey, http://gregmaxey.com/word_tips.html, 12/2/2018
'Graham Mayor - https://www.gmayor.com - Last updated - 04 Dec 2018

Dim lngY As Long, lngN As Long, lngNA As Long, lngNullorInvalid As Long
Dim oCC As ContentControl
    For Each oCC In ActiveDocument.Range.ContentControls
        If oCC.Type = 3 Or oCC.Type = 4 Then
            Select Case oCC.Range.Text
                Case Is = "Y": lngY = lngY + 1
                Case Is = "N": lngN = lngN + 1
                Case Is = "NA": lngNA = lngNA + 1
                Case Else: lngNullorInvalid = lngNullorInvalid + 1
            End Select
        End If
        DoEvents
    Next oCC

    ActiveDocument.SelectContentControlsByTitle("Not Selected").Item(1).Range.Text = lngNullorInvalid
    ActiveDocument.SelectContentControlsByTitle("Yes").Item(1).Range.Text = lngY
    ActiveDocument.SelectContentControlsByTitle("No").Item(1).Range.Text = lngN
    ActiveDocument.SelectContentControlsByTitle("NA").Item(1).Range.Text = lngNA

lbl_Exit:
    Set oCC = Nothing
    Exit Sub
End Sub