Today I am going to analyse EDT properties in standard AX application and find the most and least modified .
Why? Just to have some fun. I also hope to find out something interesting based on the results.

Methodology description
Only properties that can be modified are taken into account. For each property 2 values are calculated:
- Total - number of EDTs where the property can be modified
- Modified - number of EDTs where the property has value different from default.
Modified rate is calculated as the ratio of Modified to Total.
Properties are sorted on Modified rate in a diagram.

Analysis
Modified rate of all properties is presented in the diagram below:

Let's analyse the results.

EnumType is available on Enum EDT and must be set, that's why Modified rate is 100%.
Name must be set, so Modified rate is 100%.
Label and HelpText are usually defined, so Modified rate is very high - 88% and 81% correspondingly.
LegacyId specifies an identifier element from a previous version of Microsoft Dynamics AX, that's why Modified rate is very high - 76%.
StingSize is available on String EDT and is modified very often, Modified rate is 75%. It seems logical - usually string size is different from the default value.
ConfigurationKey property is also modified very often - 63%, perhaps in the ideal world it should aim for 100%.
Extends is modified in almost 50% of all cases.
AllowNegative is set on Integer, Int64 and Real EDTs, but not very often - Modified rate is 18%.
CountryRegionCodes is defined in 18% of all cases.
TimeSeconds is available on Time and UtcDateTime EDTs and is changed quite rarely - 9%.
NoOfDecimals is available on Real EDT and is set rarely - 8%.
AnalysisUsage and AnalysisDefaultTotal are available on all EDTs, but are set rarely - 8%.
ChangeCase is available on String EDT and is set seldom - 7%.
ReferenceTable is also defined seldom - 7%.
ShowZero is available on Integer, Int64 and Real EDTs, but is rarely modified - 5%.

All other properties are modified in less than 5% of all cases.

The following properties are never modified:
AnalysisGrouping
FormatMST
PresenceIndicatorAllowed.

Let's analyse properties per each data type.

String
I can only add that DisplayLength is modified in almost 6% of all cases.

Integer
The type is not extended very often - only 38% of all cases.

Real
The type is extended very often - 79% of all cases.

Date
The type is extended very often - 78% of all cases.
FormHelp is set in almost 13% of all cases to open a specific lookup form.

Time
I can add that TimeFormat and TimeSeparator are modified in almost 10% of all cases.
The type is extended quite rarely - 23% of all cases.

UtcDateTime
Except for common properties (Name, HelpText, Label, ConfigurationKey, LegacyId, Extends and CountryRegionCodes), other properties are very rarely modified. One third of properties is never modified.

Enum
The type is extended not often - 29%, more than third of properties is never modified.

Container
Only common properties (Name, Label, HelpText, LegacyId, ConfigurationKey) are defined. Almost one half of properties is never modified.

Guid
Only minimum of properties is modified (Name, Label, HelpText, LegacyId, Extends). 70% of all properties are never modified.

Int64
ReferenceTable is modified in almost one half of all cases - it is logical, the type is massively used for RecId relations between tables.