The bar chart illustrates the global sales of five leading mobile phone brands between 2009 and 2013.

Overall, it is clear that Samsung and Apple experienced an upward trend, with Samsung becoming the market leader by the end of the period. Conversely, Nokia and LG saw a decline in sales, while ZTE's figures remained relatively stable.

In 2009, Nokia held the lion's share of the market, selling around 440 million units. However, its sales took a nosedive over the following years, falling significantly to 250 million units in 2013. In sharp contrast, Samsung started from humble beginnings at approximately 170 million units in 2009 but gained ground rapidly. By 2013, Samsung's sales shot through the roof to reach nearly 450 million units, overtaking Nokia to take the crown.

Looking at the remaining brands, Apple's sales were minimal in 2009 but picked up steam, growing steadily to 150 million units in 2013. On the other hand, LG lost ground as its sales decreased gradually from over 100 million to around 70 million. Lastly, ZTE stayed on an even keel, with its sales hovering around 50 to 60 million units throughout the entire period.

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`*` Idioms :

`+` Hold the lion's share : Chiếm phần lớn nhất, lượng lớn nhất ( về thị trường, doanh số ).

`+` Start from humble beginnings : Khởi đầu khiêm tốn ( bắt đầu từ con số hoặc vtri thấp ).

`+` Shot through the roof : Tăng vọt lên rất cao ( như đâm thủng trần nhà ).

`+` Pick up steam : Bắt đầu tăng tốc, lấy lại đà tăng trưởng một cách mạnh mẽ.

`+` Stay on an even keel : Giữ ở trạng thái cân bằng ổn định, không biến động nhiều.

`*` Collocations :

`+` Take a nosedive : Lao dốc, giảm mạnh và nhanh chóng.

`+` Gain ground : Giành thêm thế lực, tăng trưởng mạnh mẽ.

`+` Take the crown : Giành ngôi vương, vươn lên vtri dẫn đầu.

`+` Lost ground : Mất dần vị thế, giảm sút, bị tụt lại.

`color{pink}{Yaemiko}`