Share of the Payroll Pie

The CFO of Kestrel Labs wants a pie chart for the board pack showing how the salary bill splits across the teams. Raw totals will not do — the board reads shares, and a share means each team's bill expressed against the company's whole bill.

That is the awkward bit. Each slice needs a figure from its own team and a figure covering every team at once, and the second one is not available while the rows are being gathered team by team.

employees — one row per person. department_id is the team they sit on, given as the matching id in departments; salary is annual pay in dollars; hire_date is the day they started, written year-month-day; manager_id is the id of the person they report to, and is NULL for anyone who reports to nobody.

The table already exists in the database — there is nothing to create or load.

Task: Write a query returning two columns, department_id and payroll_pct (that team's total salary bill as a percentage of the company's total salary bill, rounded to one decimal place), one row per team that has at least one employee, largest share first. Give a percentage out of 100, not a fraction of 1 — so a team holding a third of the bill reads 33.3, not 0.333.

Example output — shape only, on invented teams. The shares are percentages out of 100 and cover the whole bill between them: