出生順位別出生数：1950〜2004年
年次		総  数	第１子	第２子	第３子	第４子	第５子〜
		実　数
1950		2,337,507	634,324	654,572	384,455	247,790	415,163
1955		1,730,692	573,592	455,512	330,192	193,906	177,479
1960		1,606,041	714,827	522,867	221,595	79,718	67,017
1965		1,823,697	866,485	685,027	203,913	44,523	23,700
1970		1,934,239	878,979	753,834	245,824	40,207	15,395
1975		1,901,440	862,356	767,669	224,576	33,994	12,845
1980		1,576,889	667,683	642,573	227,604	29,901	9,128
1985		1,431,577	602,005	562,920	225,304	32,597	8,751
1990		1,221,585	531,648	459,569	192,788	30,453	7,127
1995		1,187,064	567,530	428,394	156,586	27,556	6,998
1996		1,206,555	574,054	444,571	154,457	26,532	6,941
1997		1,191,665	571,608	437,120	150,257	25,845	6,835
1998		1,203,147	583,588	439,459	148,163	25,230	6,707
1999		1,177,669	579,150	427,385	140,682	23,738	6,714
2000		1,190,547	583,220	434,964	141,011	24,644	6,708
2001		1,170,662	573,918	428,197	137,814	24,058	6,675
2002		1,153,855	571,501	421,042	131,636	23,037	6,639
2003		1,123,610	547,170	419,100	128,083	22,615	6,642
2004		1,110,721	537,913	417,647	126,117	22,458	6,586
		割  合(%)
1950		100.0	27.2	28.0	16.5	10.6	17.8
1955		100.0	33.1	26.3	19.1	11.2	10.3
1960		100.0	44.5	32.6	13.8	5.0	4.2
1965		100.0	47.5	37.6	11.2	2.4	1.3
1970		100.0	45.4	39.0	12.7	2.1	0.8
1975		100.0	45.4	40.4	11.8	1.8	0.7
1980		100.0	42.3	40.7	14.4	1.9	0.6
1985		100.0	42.1	39.3	15.7	2.3	0.6
1990		100.0	43.5	37.6	15.8	2.5	0.6
1995		100.0	47.8	36.1	13.2	2.3	0.6
1996		100.0	47.6	36.8	12.8	2.2	0.6
1997		100.0	48.0	36.7	12.6	2.2	0.6
1998		100.0	48.5	36.5	12.3	2.1	0.6
1999		100.0	49.2	36.3	11.9	2.0	0.6
2000		100.0	49.0	36.5	11.8	2.1	0.6
2001		100.0	49.0	36.6	11.8	2.1	0.6
2002		100.0	49.5	36.5	11.4	2.0	0.6
2003		100.0	48.7	37.3	11.4	2.0	0.6
2004		100.0	48.4	37.6	11.4	2.0	0.6