Escape outer variable trap in two nested foreach with Dictionary<T> - variables

Question

I have two objects that I initialize like this:
var series = new Dictionary<string,Dictionary<string,int>>()
{
{"0", new Dictionary<string, int>() },
{"1", new Dictionary<string, int>() },
{"2", new Dictionary<string, int>() }
}
var periodValues = new Dictionary<string,int>();
{
{"Jan", 0 },
{"Feb", 0 },
{"Mar", 0 }
}
Then I have another object with filled values:
var target = new Dictionary<string,Dictionary<string,int>>()
{
{ "0",
new Dictionary<string, int>()
{
{"Jan", 12 },
{"Mar", 22 }
}
},
{ "1",
new Dictionary<string, int>()
{
{"Mar", 37 }
}
},
{ "2",
new Dictionary<string, int>()
{
{"Jan", 4 },
{"Feb", 48 },
{"Mar", 22 }
}
}
}
series and target have always the same Key, while target[key].Keys (with key of type string) for any key can be a subset (at the most the same) of periodValues.Keys.
Now I want to fill series.Values according to the keys in periodValues.Keys but with the values of target[key].Value. Therefore:
foreach (var numberValue in target.Keys)
{
foreach (var period in target[numberValue].Keys)
{
periodValues[period] = target[numberValue][period];
}
series[numberValue] = periodValues;
}
But I fall in the outer variable trap...that means all series[key] for any series.Keys are equal to the last periodValues. I tried many solutions to escape the outer variable trap according to this article with no luck. Anybody knows a solution or maybe a better approach?

Answer 1

If anybody interested, I solved the problem by declaring and initializing periodValues inside the first foreach:
foreach (var numberValue in target.Keys)
{
var periodValues = new Dictionary<string,int>();
{
{"Jan", 0 },
{"Feb", 0 },
{"Mar", 0 }
}
foreach (var period in target[numberValue].Keys)
{
periodValues[period] = target[numberValue][period];
}
series[numberValue] = periodValues;
}