11.   Geller said that no one keeps reliable statistics on overdoses because the products are not controlled substances.

12.   John Money, an expert on sexual ambiguity at Johns Hopkins University, says that no reliable statistics are collected.

13.   Kersey said there are no reliable statistics yet on how many people use heroin or what percentage of them are middle class.

14.   Moreover, there are few reliable statistics on the number of blacks in Latin America, because countries there do not categorize citizens by race.

15.   New economic studies challenge this theory, which has no reliable statistics that prove it.

16.   No reliable statistics exist.

17.   Of course, reliable statistics about trading activity are inexact and difficult to come by because the identity of most trading is largely secret.

18.   One result is that election costs are exploding, Gimenez and other experts said, although there are no reliable statistics.

19.   Reliable statistics are lacking, but credible estimates suggest that tens of thousands of people have already died.

20.   Reliable statistics from neutral sources on the theft of secrets are hard to come by.