This information is recorded to indicate how many times an individual has applied for credit in the past 12 months.
A high amount of enquiries in a short space of time could be an indication of fraudulent activity, the "acceptable" average number of enquiries per a 12 month period is 5 enquiries.
Remember, if an individual has applied for a home loan or car finance, for example, they may have shopped around for credit and those enquiries should be considered as one enquiry.