Little hard to reproduce, but i think the problem is with the nan (not a number) from the missing data.
if you have a df like this:
data = [[1,2,3,4],[3,4,5,6],[np.nan,1,2,4]]
df = pd.DataFrame(np.array(data).transpose())
and create a list with the sums (like the way you are doing):
the last item would be a nan data:
[10.0, 18.0, nan]
And matplotlib wont plot it:
Possible solution:
Try to modify your lines like this, so you wont have nan data in your list:
rgn1=list(datainput['Allegany'].dropna())
Or you can simplify your code like this:
tc = datainput.sum().values
In that last line of code, the pandas df will perform a sum in all columns and handle with the missing data.