# Interpreting boxplot VS stacked histogram in example

I understand what a boxplot and histogram are supposed to show, but I'm a bit confused on how it is being presented in this graphic printout from R. The picture is taken from Beyond Multiple Linear Regression by Roback and Legler.

The response variable under study is horse's speed. In the exploratory part of this activity we have the following set of plots. The ones circled I'm having trouble interpreting. Year as a variable is self explanatory, the condition variable is a categorical variable with three levels. The data is the speed of the winning horse of the Kentucky derby for each year.

In looking at the boxplot the $$X$$ - axis is the year and the $$Y$$ - axis is the track condition. Implicitly I do get that the boxplot is showing the median speed at each track condition, but that is not being conveyed in terms of the labelling. When looking at the labelling I would gather that the "median" year is what is being captured by the boxplot. But that doesn't make much sense in this context. Am I missing something in what I'm looking at? because I don't see how you can have median year for an event having one occurrence each year.

The graphic I'm discussing: