1.   The national income, too, is hard to calculate exactly in the frequent absence of reliable national statistics.

2.   There are, however, no reliable statistics relating to social class and illness over the years.

3.   There are no reliable statistics for the number of deaths in the battle.

4.   Although reliable statistics remain elusive, legal experts say most cases have been prosecuted under various state laws rather than the federal statute.

5.   Although there are no reliable official statistics, fires alone account for thousands of deaths every year.

6.   And, unsurprisingly, reliable statistics on land ownership are hard to come by.

7.   Because jobs are often short-term or part-time, no reliable statistics are available showing how many retired people are now working.

8.   Because computer game addiction is relatively new, there are no reliable statistics on the depth of the problem, Dr. Orzack said.

9.   After unearthing a few inconclusive studies, he began to hunt around for a data set large enough to yield reliable statistics.

10.   Even the lack of reliable statistics about small business illustrates its lowly status.