The pie-charts below give the percentage distribution of employees in different Departments in XYZ Company Ltd. during the years 2005 and 2006. A - Administration; B - Operations; C - Sales & Marketing; D - Finance & Accounts; E - Corporate HQ.

2005 (total employees 18,000): A 22%, B 23%, C 18%, D 29%, E 8%.
2006 (total employees 20,000): A 24%, B 26%, C 20%, D 20%, E 10%.
In which department is the variation in strength (absolute change) the maximum in 2006 compared to 2005?
Rather than compute both years' headcounts and subtract, split each department's change into two parts: the change that comes purely from the company growing by 2,000 employees, and the change that comes from the department's own share shifting. Using new% for the 2006 share and old% for the 2005 share, and old total = 18,000:
\[ \Delta = (\text{new\%} \times 2000) + (\text{new\%} - \text{old\%}) \times 18000 \]
The magnitudes are 840, 1060, 1220 and 560. Finance & Accounts shows the biggest swing because it lost 9 percentage points of the company's headcount while the company itself was expanding, so both effects push in the same direction and add up.
Let's summarize:
Finance & Accounts (D) has the maximum absolute change in strength.