How to add my element in Qt Vertical layout from top to bottom?

Question

I need to add widgets from top to bottom, actually when I add new widget it is adding it automatically to bottom.

self.chartLayout = QtWidgets.QVBoxLayout()
for (adding graph each loop)
    self.chartLayout.addWidget(self.chartVs[lastIndex])

At the end I have, something like :

Graph1
Graph2
...
Graphx

I need to have :

Graphx
..
Graph2
Graph1