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_16649 ( "#" real, "Episode" text, "Air Date" text, "Rating" text, "Share" real, "Rating/Share 18\u201349" text, "Viewers (m)" text, "Timeslot Rank" real, "Night Rank" text, "Overall Rank" real )

### Question ###
what's the overall rank with rating/share 18 49 of 2.1/5

### Accurate SQL ###

SELECT COUNT("Overall Rank") FROM table_16649 WHERE "Rating/Share 18\u201349" = '2.1/5'