Can you help me to interpretate these two boxplots?

hlsmith

Less is more. Stay pure. Stay poor.
#2
Is this an assignment?

What is on the y-axis? And you wouldn't calculate, but report it from the figures correct?
 
#3
This isn't an assignment but I would like to interpret the graph in a proper way. For example, I try to calculate the percent difference between the two medians of the left-preferent ones (see Table 1): 11.35kg and 10.40kg. But the result (11.35kg - 10.40kg/ 10.40kg x 100% = + 9.1%) does not correspond to the Q2 median of the corresponding boxplot of the left-handed children of the 1st grade. The y axis represents the performances of the children using their dominant hand for each grade of primary school.
 
#4
Sorry, the y axis represents the percent differences between dominant and non-dominant hand and the x axis represents the performances of the children using their dominant hand for each grade of primary school.