A zeroth order approximation of the quality of the dataset can be easily obtained by simply examining the distribution of target value, PCE. The average of the PCE values in the dataset is 8.43±3.09% and the median is 9.02%, with maximal and minimal values of 15.71% and 0.01%. This covers a large range of the PCE values reported in the literature with the data skewed more toward large values. However, the PCE values top out at 15.71%, which can be explained by the age of the included papers. The distributions of values that make up the PCE equation are similar, although VOC values are distributed more normally (Figure ). To ensure the accuracy of the original PCE data, we calculated the number of PCE values that deviated from the PCE calculated from the analytical equation. We found that 101 (18.1%) of original PCE values deviated by more than 1% multiplied by the calculated PCE. This allowed us to quickly identify problematic data points, which were most often due to human errors in data entry: either 𝐹𝐹 × 100, or data was taken from the wrong device. Those points were amended, and the calculated PCE was used as the final target variable.