How to decrease tick mark labels in Area/Line combo chart?
 

I have an area/scatter line combo chart. I'm plotting weeks for two years on
the X axis. It's actually consists of 2 columns of data. Column B will have
the weeks as 1,2,3, and 4 then the same number again 1,2,3,4. While col A
will show the period (every 4 weeks = one period) for a total of 13 period
for the first year and the same for the second year. Plotting 104 weeks on
the X axis makes it hard to see/read. I couldn't adjust the 'number of
categories between tick mark lables', I guess because the chart contains area
type. I have tried to add a dummy scatter line, so I can adjust the labels
from showing each and everyone to may be show one every 3 weeks, but the
option still grayed out.
Any idea on how to make this legible?

Thanks.
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when u change the way u look @ things, the things u look at change.