A) Box-and-whisker plot of cotinine in urine [μg/24 h] from 1995 until 2019. Box-and-whisker plot represent medians (red horizontal line) with 25% and 75% percentiles (boxes), 5% and 95% percentiles (whiskers), and outliers (diamonds). B) Time trend for 1-OH-Pyr (black), 1-Nap, 2-Nap, and the sum of 1-/2-/3-/4-/9-OH-Phe [μg/24 h] from 1995 until 2019. Plot represent medians (symbol + line) with 25% and 75% percentiles (shaded area). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)