Clarify description for "Number of Perceived Objects"

PerceivedObjectContainer ::= SEQUENCE {

    -- @details numberOfPerceivedObjects

    -- The total number of detected objects by the station at the time of generating the message.

    -- Due to the dynamic message generation rules, this number does not have to reflect the number

    -- of objects included in this message but states the number of objects known to the sender at

    -- the time of generating the message.

    numberOfPerceivedObjects    NumberOfPerceivedObjects DEFAULT 0,

    perceivedObjects            SEQUENCE SIZE(1..128, ...) OF PerceivedObject

}