It will return average of your load average....
on second thoughts (and further reading of the documentation!), May be what you need is the xyseries.
http://docs.splunk.com/Documentation/Splunk/latest/SearchReference/Xyseries
You may have to create a dummy field with the Y-axis label like so:
... | eval y_field = "load_times" | xyseries date_time y_field, load_time
I haven't used this but I have a feeling this will suit your case.
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