Database: world_development_indicators
Question: What is the subject of the series SP.DYN.AMRT.MA and what does it pertain to?
SQL: SELECT DISTINCT T1.Topic, T2.Description FROM Series AS T1 INNER JOIN SeriesNotes AS T2 ON T1.SeriesCode = T2.Seriescode WHERE T1.SeriesCode = 'SP.DYN.AMRT.MA'