Can't Load Dates Pre-1960s

[Sky -Byte]

Hello everyone! I'm trying to create a streamgraph using some data from letters written in the early 1900s. Ex:      
9/21/1911 | E.W. Middlemast | Madras Port Trust | Cambridge, UK | Madras, India | Employment for Ramanujan | Madras Port Trust
2/9/1912 | Srinivasa Ramanujan | Madras Port Trust | 7 Summer House, Triplicane, Madras, India | Madras, India | Employment for Ramanujan | Madras Port Trust
2/15/1912 | The Chief Accountant | Srinivasa Ramanujan | Madras Port Trust, Madras, India | 8 Summer House, Triplicane, Madras | Employment for Ramanujan | Madras Port Trust 

I would like to use the graph to show how the frequency of certain people writing, certain places being written from, and certain topics being written about, changed over time. However, I can't seem to parse the date data. I've experimented a little, and it looks like RAWGraphics can't discern dates that are earlier than the 1960s? It looks like it rolls the earlier ones over into the next century, instead. It assumes that 1912 is 2012, 1940 is 2040, etc. Makes for a weird graph! 

Is this true, that the code can't load pre-1960s dates? Please let me know!