Beacuse the neutrals did a balancing act by giving extra seats to PMLN and PPP. Otherwise they were totally wiped out. Imagine after Panama case and they being totally exposed doing corruption, how the hell they managed to get any seats at all.Even in 2018 they got 20-25 extra seats by the help of their neutrals ... Khwaja Asif is one big example who was loosing big time until 10-11PM and then the results stopped coming and the he just WON magically after talking to the neutrals.
They would not get more than 10-12 seats if the elections of 2018 were 100% free/fair.