-- Database schema
| singer : Singer_ID [ INT ] primary_key , Name [ TEXT ] , Birth_Year [ INT ] , Net_Worth_Millions [ INT ] , Citizenship [ TEXT ] | song : Song_ID [ INT ] primary_key , Title [ TEXT ] , Singer_ID [ INT ] song.Singer_ID = singer.Singer_ID , Sales [ INT ] , Highest_Position [ INT ] |
-- -- Show different citizenship of singers and the number of singers of each citizenship.

SELECT Citizenship ,  COUNT(*) FROM singer GROUP BY Citizenship;