Table 5. Statistics for 10 most common double turn type combinations in CompleteSet.

Rank	Double turn type	Count	Perc.	Cumulative Perc.
1	AD-AD	3,307	61.6	61.6
2	AD-AZ	470	8.7	70.3
3	AD-AB2	223	4.2	74.5
4	Pa-ad	199	3.7	78.2
5	AD-AB1	137	2.6	80.7
6	AD-AG	121	2.3	82.9
7	pD-AD	119	2.2	85.2
8	Pd-dD	103	1.9	87.1
9	Pd-dN	84	1.6	88.7
10	PcisD-cisDA	76	1.4	90.1
	other	533	9.9	100.0
	All	5,372	100%	100%

Double turns overlap by three residues (i.e., 1-2-3-4 and 2-3-4-5).