They were and they digressed under the very same ruling which affected to the succe
Stats can be manipulative but the history can't.
The reasons their record were better because they assumed the power when the nation had stable economy during that times. When they left, unstable economy was dumped on their successors. How do you expect them to reconcile the situation? Start from the beginning; clean the mess and stabilize the economy all over again.
Under Ayub Khan through Marshall Law; Pakistan was reputed to be Asia Tiger in economy but 1971 happened and that was tip of the iceberg which later changed the fate of Pakistan for worse.
Under Zia Haq through Marshall Law: He assumed the power when the economy was stable. Then all went to downhill after 80s with the policy of Taliban. That plagued the economy till 90.
Democracy came back and stabilized the economy. The economy was starting to grow. Then Musharraf happened. Again it went down the drain as TTP and MQM flourished under his ruling and those problems were dumped on democracy after 7-8 years.
Again, democracy is back and cleaning the mess made by Musharraf through Marshal Law. Cleaning the mess meaning TTP+MQM.
Those Generals took over the leadership when the economy was stable. When they left, unstable economy along with the mess dumped on their successors [democracy] to deal with. Now you can understand why the stats can be manipulate. In the history of Pakistan, democracy had played vital role in repairing the damage inflicted on the economy by Generals. Generals don't know how to rule, and precisely why they always leave the unstable economy on their successors [democracy] to clean the mess.
Even today, democracy under PMLN is cleaning the mess and stabilizing the economy. As the economy starts to stabilize as the economic growth shapes positively, i am afraid General may or may not take over again and take advantage of the hard work done by democracy and leave the mess after its completed term on democracy to deal with. It is vicious cycle that doesn't let Pakistan grow to fulfill its potential unfortunately.
Can you honestly blame on PMLN for the mess that was created [TTP+MQM] under the ruling of Musharraf? PMLN came at the worst possible time, and in the short period of time, the mess was cleaned by huge portion, the economy is starting to stabilize and economic growth is shaping nicely for present and future until Marshall Law happens again and set Pakistan back.