-- Database schema
| chapters : id [ INTEGER ] primary_key , Act [ INTEGER ] , Scene [ INTEGER ] , Description [ TEXT ] , work_id [ INTEGER ] | characters : id [ INTEGER ] primary_key , CharName [ TEXT ] , Abbrev [ TEXT ] , Description [ TEXT ] | paragraphs : id [ INTEGER ] primary_key , ParagraphNum [ INTEGER ] , PlainText [ TEXT ] , character_id [ INTEGER ] , chapter_id [ INTEGER ] | works : id [ INTEGER ] primary_key , Title [ TEXT ] , LongTitle [ TEXT ] , Date [ INTEGER ] , GenreType [ TEXT ] |
-- -- Gives the average number of chapters in Shakespeare's 1599 work.

SELECT CAST(COUNT(T1.id) AS REAL) / COUNT(DISTINCT T2.id) FROM chapters AS T1 INNER JOIN works AS T2 ON T1.work_id = T2.id WHERE T2.Date = '1599';