SELECT EXTRACT(YEAR FROM "Date") AS "Year", COUNT(*) AS "NumberOfDays" FROM "Prod"."IMETA_Calendar" GROUP BY EXTRACT(YEAR FROM "Date") ORDER BY EXTRACT(YEAR FROM "Date");
Seems odd to be using extract year from date when you have an FY column.
I get some output:
Nothing you've shown produces that output. I would suggest you simplify and make self-contained a script-based test case, ideally using psql, that you can run and share, asking questions regarding the main piece here which is creating a table, populating it with data, and querying it. Once you get that part solid you can figure out how to incorporate your spreadsheets - which is mostly outside the realm of on-topic help for a PostgreSQL mailing list.