Zooming In and Out using ArcPy with ArcGIS Pro?

I have code that zooms a layout to a bookmark and then exports that layout to PDF. This step helps me produce maps on a large scale because I have about 40 bookmarks. However, if someone asks me to create the maps again but zoomed in or out more than that creates a problem because then I have to change all the bookmarks. I'm hoping there is some kind of code that would zoom to the bookmark and then I could tell it to zoom in or out a certain amount from there.

Here is the code I have currently:

import arcpy

p = arcpy.mp.ArcGISProject(r'C:\arcGIS_Shared\Python\CenterHeatMaps.aprx')
lyt = p.listLayouts("Layout_King")[0]
mf = lyt.listElements("MAPFRAME_ELEMENT", "Map*")[0]
bkmks = mf.map.listBookmarks()
m = p.listMaps()[0]
OnLyrList = m.listLayers('Topographic')
OnNxtList = m.listLayers('Open_GoHealth_Centers')

CenterList = m.listLayers("CASum*")

#Loop through center layers that begin with 'SumWithin'
for center in CenterList:

   #Loop through all bookmarks until finding a match for the active center
    for bkmk in bkmks:       
        if bkmk.name == center.name[19:]:

            #Turn off all layers

               lyrList = m.listLayers()
               for lyr in lyrList:
                   lyr.visible = False

            #Turn on desired layers
               for lyr in OnLyrList:
                   lyr.visible = True
               for lyr in OnNxtList:
                   lyr.visible = True
               center.visible = True


            #Zoom to active bookmark
               mf.zoomToBookmark(bkmk)

            #Change Layout Title
               for elm in lyt.listElements("TEXT_ELEMENT"):
                   elm.text = "Annual_CA Summary by Block 2017 - " + center.name[19:]

            #Export to PDF
               lyt.exportToPDF(r"C:\arcGIS_Shared\Python\Export\CenterHeatMaps_CA" + "\\Annual_CA" + center.name[15:] + ".pdf")

               print(center.name[15:])

Is what I'm asking possible? I haven't been able to find anything online.

Answer

To zoom in or out on the current extent of a map frame you should be able to use the scale property of the map frame's Camera object.

For example, this code will zoom out 5%:

mf.camera.scale = mf.camera.scale * 1.05