CREATE TABLE table_21166 ("District" CLOB, "Vacator" CLOB, "Reason for change" CLOB, "Successor" CLOB, "Date successor seated" CLOB)

In district New York 10th, what was the reason for change?
SELECT "Reason for change" FROM table_21166 WHERE "District" = 'New York 10th'
SELECT "Reason for change" FROM "table_21166" WHERE "District" = 'New York 10th'