Based on the graph below, what is the most likely explanation for what happened half through year 15

Astore manager timed janette to see how long it would take her to fold and put away a sweater, a shirt, a pair of pants, and a scarf. it took her 26.1 seconds for the shirt, 24.3 seconds for the sweater, 32.8 seconds for the pants, and 18.2 seconds for the scarf. what was the average time it took janette to fold and put away all four items? during a catered lunch, an average of 4 cups of tea are poured per minute. the lunch will last 2 hours. how many gallons of tea should the caterer bring if there are 16 cups in one gallon?