Table 5. Number of private sector establishments by age Mining, Quarrying, and Oil and Gas Extraction Age Class March 1994 March 1995 March 1996 March 1997 March 1998 March 1999 Less than one year 1,863 2,062 1,816 2,160 1,999 1,609 1 year _ 1,445 1,590 1,432 1,693 1,468 2 years _ _ 1,182 1,389 1,239 1,409 3 years _ _ _ 1,083 1,244 1,006 4 years _ _ _ _ 975 1,071 5 years _ _ _ _ _ 845 6 years _ _ _ _ _ _ 7 years _ _ _ _ _ _ 8 years _ _ _ _ _ _ 9 years _ _ _ _ _ _ 10 years _ _ _ _ _ _ 11 years _ _ _ _ _ _ 12 years _ _ _ _ _ _ 13 years _ _ _ _ _ _ 14 years _ _ _ _ _ _ 15 years _ _ _ _ _ _ 16 years _ _ _ _ _ _ 17 years _ _ _ _ _ _ 18 years _ _ _ _ _ _ Born before March 1993 22,423 20,379 18,771 17,512 16,461 15,023 Total 24,286 23,886 23,359 23,576 23,611 22,431 Age Class March 2000 March 2001 March 2002 March 2003 March 2004 March 2005 Less than one year 1,700 1,835 1,950 1,564 1,719 1,970 1 year 1,289 1,370 1,521 1,548 1,343 1,503 2 years 1,203 1,185 1,202 1,291 1,332 1,189 3 years 1,221 1,078 1,044 1,042 1,185 1,218 4 years 905 1,096 950 835 951 1,127 5 years 965 826 978 853 793 885 6 years 784 869 730 907 794 731 7 years _ 731 804 679 850 746 8 years _ _ 671 726 628 803 9 years _ _ _ 647 702 575 10 years _ _ _ _ 609 666 11 years _ _ _ _ _ 573 12 years _ _ _ _ _ _ 13 years _ _ _ _ _ _ 14 years _ _ _ _ _ _ 15 years _ _ _ _ _ _ 16 years _ _ _ _ _ _ 17 years _ _ _ _ _ _ 18 years _ _ _ _ _ _ Born before March 1993 14,016 13,236 12,472 11,708 11,344 10,996 Total 22,083 22,226 22,322 21,800 22,250 22,982 Age Class March 2006 March 2007 March 2008 March 2009 March 2010 March 2011 Less than one year 2,398 2,800 2,669 2,563 2,001 2,498 1 year 1,746 2,025 2,353 2,140 2,002 1,630 2 years 1,363 1,539 1,769 1,987 1,777 1,780 3 years 1,081 1,264 1,398 1,567 1,705 1,591 4 years 1,121 989 1,175 1,253 1,341 1,551 5 years 1,049 1,041 906 1,070 1,140 1,275 6 years 822 992 977 840 984 1,039 7 years 705 792 947 903 775 902 8 years 704 662 756 897 861 746 9 years 740 651 649 725 832 786 10 years 546 705 622 608 677 775 11 years 637 523 672 590 580 662 12 years 554 602 499 634 565 576 13 years _ 530 582 483 597 558 14 years _ _ 503 544 463 568 15 years _ _ _ 489 518 454 16 years _ _ _ _ 483 502 17 years _ _ _ _ _ 457 18 years _ _ _ _ _ _ Born before March 1993 10,683 10,323 10,041 9,729 9,431 9,192 Total 24,149 25,438 26,518 27,022 26,732 27,542 Age Class March 2012 Less than one year 2,969 1 year 2,102 2 years 1,412 3 years 1,613 4 years 1,476 5 years 1,425 6 years 1,171 7 years 995 8 years 833 9 years 717 10 years 765 11 years 754 12 years 641 13 years 546 14 years 547 15 years 561 16 years 450 17 years 478 18 years 441 Born before March 1993 9,050 Total 28,946 NOTE: A '_' indicates that the data are not available and a 'N' indicates that the data do not meet BLS disclosure standards.