Health care and education have replaced manufacturing as the biggest employers in the Illawarra as the population ages and the region continues to be transformed into a service and education-based economy.A new investigation by the Mercury shows the region's biggest employers are now the area health service, the education department and BlueScope Steel - in that order.As service providers continue to grow, the University of Wollongong and Wollongong City Council are also placed high in the list of top jobs providers.And as people aged over 65 continue to make up a larger proportion of the population, retirement services are booming.The Illawarra Retirement Trust and Warrigal Care are both listed in the region's top 10 employers.The movement towards a service-based economy is a pattern seen across the country, particularly in NSW, Illawarra Regional Information Service director Simon Pomfret said."It's a significant growth sector across the country," he said."Certainly that's where the growth in our employment has been in the past 10 years."It's a forced diversification as well - every traditional sector, particularly manufacturing, is continuing to rationalise."The other sectors relatively are getting bigger."While the changes have been difficult for some, the diversification has had benefits for the region's economy, which won't be chained to the fluctuations in the coal and steel industry.Of today's top 10 individual employers, six are education, health care or aged care providers.Industry-wide, health and retail are the two major employers, and have been for several years. Construction and education are the next two biggest industries in terms of total employment numbers. Manufacturing has slipped to sixth place.Total numbers employed in manufacturing are about 13,000, down from about 24,000 in early 2008, IRIS figures show.Aged care services will continue to grow, with the number of people aged over 65 set to double by 2050. In Shellharbour, almost three-quarters of the population will be over 65 in a decade.