question: What is the average upper index MJ/Nm 3 for the upper index Kcal/Nm 3 entry of 19,376?
answer: SELECT AVG(upper_index_mj__nm_3) FROM table_name_70 WHERE upper_index_kcal__nm_3 = 19 OFFSET 376
context: CREATE TABLE table_name_70 (upper_index_mj__nm_3 INTEGER, upper_index_kcal__nm_3 VARCHAR)