This proposal shows a month’s energy usage in the context of previous months’ so that the reader could easily see the longer tendency. After experiments, two distilled proposals with different accumulative diagrams were made. In the first proposal, different screen patterns are assigned to diferent months, so the graph as a whole could still be readable when multiple monthly graphs are overlapped. In the second design, simple bar graphs in different colors are used to express different monthly usages. The bars in the latest month’s graph is thickened to be easily recognizable.