The given graph illustrate the average contract cost on a month basis of four cellular companies in a European nation between January and September in 2012.
Overall, there was an increase in the average cost of contract in almost companies, except Sim TX, which witnessed a reverse pattern throughout the period. Notably, despite commencing with the lowest point, the average cost of contract in Alpha surpassed that of other companies to become the leading by the end of the period examined.
At the outset, from January-June period, the average cost of contract of Domo company started at the highest position (15 euros), followed by the figure for Lex company (~13 euros) and Sim TX company (~9 euros), and Alpha company, by contrast, began at the lowest point (5 euros). Then, while the figure for Domo company rose gradually by 5 euros by July, despite a slight drop to about 17 euros in April and that of Sim TX company increased to just under 15 euros, the figure for Lex and Alpha company hovered around 13 euros and 5 euros respectively in the same period.
In the following years, the average contract cost of Domo company rose to about 23 euros in September, and it is overcame by that of Alpha company with a noticeable rise to 25 euros, which became the dominant company in the average cost of contract by the same month. A less remarkable trend can be observed in Lex company, whose figure climbed to 19 euros; in contrast, Sin TX company experienced a gradual drop to around 7 euros by the end of the period examined.