As near as I can tell, anything that increases tax revenue increases contributions for health and education. They all appear to be loosely proportional to each other with health/education contributions having diminished ability to rise the closer to the expenditures they reach (they can go over the expenditures though).
Increase salaries. See the "pop-up bubbles" that explain the various contributions on the Finance > financial statement page, and all of them basically say that workers or people in the country contribute, with higher paid ones contributing more.