SNMP value with % in string not producing graphs

[mrjibbles]

Hi,
I have 3 data compression boxes (Storwize) with have a OID value for memory (.1.3.6.1.4.1.24335.1.2.1.3) and CPU usage (.1.3.6.1.4.1.24335.1.2.1.1) but the value returned from the poll is not just a figure (see attached file)
I believe that this is causing my graphs not to display any values (see attachment)
How would I remove the extra character strings and just get the values into the graphs?
Thanks in advance.
Giles