Problem solving has been characterized as one of the 'employability skills' due to the high demand for such abilities in a modern workplace. Most universities do not monitor progress of the generic problem-solving skills (PSS) of their students due to a lack of available assessment tools. We used previously reported 15-min tests to measure the generic PSS of students over the first three years of university. More than 600 students participated in this study, including 144 who wrote PSS tests in Year 1 and then again in Year 3 of their studies. Two versions of the PSS test were administered in September and December of both years. We observed a non-linear increase in PSS test scores with a significant growth during the first three months of Year 1, a similar increase over the next 21 months, then no change during the first three months of Year 3. Further studies are necessary to pinpoint the instructional techniques and situational factors facilitating the PSS development of students over the first three years of studies. Moreover, the plateau we observe in the third year indicates that proactive steps by universities and individual instructors are required to advance this important skill set in upper-year students.