user: Question: What is the sum of Year, when Role is "Himself", and when Notes is "Celebrity guest alongside YG Family"?
Columns: ['Year', 'Title', 'Role', 'Network', 'Notes']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [2004.0, "Epik High's Love and Delusion", 'Himself', 'Mnet', 'Series regular']
SQL:

assistant: SELECT SUM("Year") FROM "Table" WHERE "Role" = 'Himself' AND "Notes" = 'Celebrity guest alongside YG Family';