Spline Area Charts are Spline Charts with the area between the X axis and the spline colored (it may be colored differently from the spline). In this sample X axis holds the categories (month names), Y axis - relative humidity in percents.
This spline area chart shows average humidity over the year in two cities: Gotham and Mos Eisley. There are two spline area series, light blue one for Gotham City and dark blue for Mos Eisley. Batman writer and editor Dennis O'Neil vividly described Batman's place of residence: "Batman's Gotham City is Manhattan below Fourteenth Street at eleven minutes past midnight on the coldest night in November."; you almost never see clear skies in any of the novels, books, movies and other artwork. No wonder we can see such high humidity all over the year.
Mos Eisley shares a lot of traits with Gotham, Obi-Wan Kenobi once said to Luke Skywalker: "Mos Eisley Spaceport. You will never find a more wretched hive of scum and villainy. We must be cautious.". But climate is totally different here: Tatooine is sparsely inhabited desert planet located in the galaxies Outer Rim Territories; Tatooine is oppressed by a scorching suns (Tatoo I and Tatoo II), resulting in the world to lack the necessary surface water. Unfortunately, neither Jawa and Tusken Raiders, nor Hutt Clan had ever had any interest in funding a meteorological observation network, and this explains why there are two points missing in the data. To add missing point in the AnyChart Data Set you need to put "null", "NaN" or "missing" instead of the value.