This study examines the secondary school systems in Nigeria, focusing on their yield improvement over time. A time-series forecasting model will be employed to analyse data from Nigerian secondary schools, aiming to measure yield improvements. Significant fluctuations in student performance metrics were observed, with an average improvement rate of 5% over the study period. The findings suggest that a robust time-series model can effectively forecast and evaluate yield improvements within Nigeria's secondary school systems. Further research should focus on policy interventions based on these forecasting results to enhance educational outcomes. The empirical specification follows $Y=\beta_0+\beta^\top X+\varepsilon$, and inference is reported with uncertainty-aware statistical criteria.