Hi Nalaka,

I'm confused why the actual falling to zero is a problem, so I won't
address this. Not sure how that relates to your last sentence, which
I'll offer some a workaround. I don't know of an easy way to combine
a solid line that turns into a dotted one. You can trick it by having
2 series instead of 1. Then format 1 as solid and 1 as dotted. This
is hard to explain, but here goes.

Imagine data in cells "A1" thru "C12" ... like this:

Mo Val Val
--- ---- ----
1 10
2 20
3 30
4 40
5 50
6 45
7 55 55
8 60
9 90
10 10
11 88
12 87

The value for the 1st mo is 10, which is cell "B1". The value for the
12th month is in "C12" or 87.

Create a chart with 2 Series. The first Series will have the values
"B1:B7". Notice the 7th month of the 1st series equals the value in
the 2nd series. This makes the series lines connect.

The second Series will be the values "C1:C12". "C1" is not a typo.
The first 6 values of the 2nd series are empty. This is necessary to
make the 2nd series appear to shift forward and line up.

Now simply format 1st series as solid line and the 2nd as a dotted
line.

This is ugly and may not even be what you're looking for.

Hope it helps,
Steve Hieb