Table 4.

National population estimates by HydrAP ranks in CONUS by NLA survey year

	2007		2012
HydrAP	Population (std error)	% Population (std error)	Population (std error)	% Population (std error)
0	8689.2 (1209.8)	23.1 (2.7)	6886.0 (1015.4)	12.8 (1.8)
1	4331.0 (627.6)	11.5 (1.7)	9803.9 (1270.0)	18.3 (2.2)
2	6958.6 (933.9)	18.5 (2.3)	13457.2 (1277.6)	25.1 (2.3)
3	1888.0 (508.8)	5.0 (1.3)	2937.2 (635.8)	5.5 (1.2)
4	6257.6 (923.7)	16.6 (2.2)	8542.4 (1713.9)	15.9 (2.8)
5	4229.1 (586.7)	11.2 (1.5)	4154.0 (799.3)	7.7 (1.4)
6	2671.5 (394.2)	7.1 (1.1)	3210.2 (626.5)	6.0 (1.2)
7	2652.7 (436.9)	7.0 (1.1)	4625.5 (705.5)	8.6 (1.3)
TOTAL	37677.8 (1914.9)	100	53616.4 (2653.7)	100