Chart of Punjabi language speakers in Pakistan (1951-1998)

Punjabi is the most widely spoken language in Pakistan. Punjabi is the provincial language in the Punjab Province of Pakistan. Punjabi is spoken as a native language by over 44.15% of Pakistanis. About 70.0% of the people of Pakistan speak Punjabi as either their first or second language, and for some as their third language. Lahore, the capital of the Punjab Province of Pakistan, is the largest Punjabi-speaking city in the world. 86% of the total population of Lahore is native Punjabi and Islamabad, the capital of Pakistan, is 72% native Punjabis at 3rd after Faisalabad where 98.2% are native. There are also large number of Punjabi speakers in Karachi.

Reference 1: Population of Pakistan, Percentage and Punjabi speakers.

Reference 2: 1951, 1961, 1972, 1981 and 1998.

Source: http://en.wikipedia.org/wiki/Punjabi_language