CREATE TABLE table_name_36 (stage INTEGER, finish VARCHAR(255), year VARCHAR(255), leader_at_the_summit VARCHAR(255))
What is the highest stage number for a year later than 1948, leader at the summit was group, and finish was Bagnères-De-Bigorre?
    
SQL: SELECT MAX(stage) FROM table_name_36 WHERE year > 1948 AND leader_at_the_summit = "group" AND finish = "bagnères-de-bigorre"