How to count the {ITEM.LASTVALUE} in history values?

[arduinozz]

I want to count the {ITEM.LASTVALUE} in history values.
I used the function of count(/host/key,300m,"like","{ITEM.LASTVALUE}"), but I cannot get the right count value.
Who can tell me why and how to get the right count value?

[roman.rajniak]

Have you found solutions to this problem?