Keep record of Maximum (or other statistics) achieved value in a cell

If you'd like to keep automatically the record of some statistics (max, mean, average, standard deviation, etc.) related to your set of data that are subject to change periodically over time, then a simple macro can help. 

Here is an example VBA code that you can copy and paste in your VBE window appearing for your worksheet after using the ALT+F11 shortcut. This code sample, you see below, will record just the maximum value of the SUM of numbers entered within A1:A10 range. It can be easily modified for any other special purpose.

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim myVar As Double
myVar = Range("A11").Value 'Sum of numbers in a range
Range("Z100").Value = myVar    'Replace Z100 with any other cell, if needed
If myVar > Range("A12").Value Then Range("A12").Value = Range("Z100").Value
End Sub

As shown in the fragment of my worksheet, the data are entered in A1:A10 range. Cell A11 contains formula =SUM(A1:A10). The result, updated each time you change something in the worksheet, is displayed in cell A12. The helper cell location (Z100 here) can be changed in the code at your will.