rows property
Rows is how many rows they held between them, as the REGISTER recorded them when each was materialised — not a count of what the drop deleted, which is gone by the time this answers.
Please note: This property should have been non-nullable! Since the specification file does not include a default value (using the "default:" property), however, the generated source code must fall back to having a nullable type. Consider adding a "default:" property in the specification file to hide this note.
Implementation
int? rows;