Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_59 ( upper_index_kcal__nm_3 VARCHAR, fuel_gas VARCHAR, lower_index_mj__nm_3 VARCHAR )

### Question ###
What is the Upper index Kcal/ Nm 3 of iso-butane, and a Lower index MJ/ Nm 3 smaller than 84.71?

### Accurate SQL ###

SELECT COUNT(upper_index_kcal__nm_3) FROM table_name_59 WHERE fuel_gas = "iso-butane" AND lower_index_mj__nm_3 < 84.71