If you see the map, those countries who performed worst in GDP growth has lower Gini index. Like see the one of China.
GDP growth alone does not help the middle class if the bulk of the gains go to a few billionaires.
I suggest you also look at the the last column, the aggregate change in middle class annual expenditure. It was $80 million in Pakistan...the 4th highest after China's $1.8 billion, India's $256 million and Indonesia's $168 million.
Haq's Musings: Upwardly Mobile Pakistan on 66th Independence Day