human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: State (class), Vacator, Reason for change, Successor, Date of successors formal installation
###Question: What is the total number of dates of successor formal installation when the vacator was Joshua Clayton ( F )?
gpt
SELECT COUNT Date of successors formal installation FROM table WHERE Vacator = Joshua Clayton ( F )