<|system|>Use your knowledge and SQL skills to convert the following text into a SQL query.
Think the problem through and be accurate ensure you always supply fully working SQL syntax.

SQL Statments should be wrapped in <codestart type="sql"> and </codeend> tags.

Example output:
<codestart type="sql">SELECT * FROM table_name;</codeend>
<codestart type="sql">SELECT column_name FROM table_name WHERE column_name = 'value';</codeend><|end|><|user|>What was the number of season number entries that had US Viewers of 12.30 million?

SQL Table Create Statement:
CREATE TABLE table_21781578_2 (season_no VARCHAR, us_viewers__millions_ VARCHAR)<|end|><|assistant|><codestart type="sql">SELECT COUNT(season_no) FROM table_21781578_2 WHERE us_viewers__millions_ = "12.30"</codeend><|end|>