YearMultiparous MothersInterpregnancy Interval
Short IPIIPI of 12-35 MonthsIPI of 36 Months and over
NumberRateNumberRateNumberRate
Number & Rate of Live Births by Interpregnancy Interval and by Year,
Marquette County, Michigan 1989-2015
1989550  84  152.7267  485.5199  361.8
1990547  103  188.3266  486.3178  325.4
1991537  95  176.9246  458.1196  365.0
1992254  41  161.4123  484.390  354.3
1993515  75  145.6257  499.0183  355.3
1994460  77  167.4201  437.0182  395.7
1995390  64  164.1168  430.8158  405.1
1996357  63  176.5164  459.4130  364.1
1997328  55  167.7154  469.5119  362.8
1998313  45  143.8145  463.3123  393.0
1999308  39  126.6147  477.3122  396.1
2000333  51  153.2155  465.5127  381.4
2001322  43  133.5142  441.0137  425.5
2002331  53  160.1155  468.3123  371.6
2003329  54  164.1146  443.8129  392.1
2004322  61  189.4155  481.4106  329.2
2005309  47  152.1142  459.5120  388.3
2006342  51  149.1151  441.5140  409.4
2007382  73  191.1193  505.2116  303.7
2008324  65  200.6150  463.0109  336.4
2009312  59  189.1151  484.0102  326.9
2010301  49  162.8158  524.994  312.3
2011287  41  142.9147  512.299  344.9
2012343  58  169.1175  510.2110  320.7
2013256  50  195.3119  464.887  339.8
2014317  45  142.0155  489.0117  369.1
2015308  45  146.1157  509.7106  344.2

Notes:

Rates are per 1,000 multiparous mothers.
Inter-pregnancy Interval (IPI) is the time in months between the date of last menstrual period of current pregnancy and the date of previous live birth among multiparous mothers. (This definition of IPI is sometimes called the "birth-to-birth interval, minus 9 months.")

Short IPI
The IPI is less than 12 months.

Source: 1989 Michigan Birth Certificate Registry;1990-2015 Geocoded Michigan Birth Certificate Registries.
Division for Vital Records & Health Statistics, Michigan Department of Health & Human Services