Table 2. Step-driven ventilatory volume, as a fraction of concurrent volume, during inspiration and expiration.

Subject	Insp	Exp
1	−17.2%	15.2%
3	−9.8%	9.3%
4	−7.7%	7.6%
5	−10.5%	7.5%
6	−9.6%	9.2%
7	−11.5%	8.2%
8	−9.9%	8.1%
9	−10.1%	9.6%
10	−14.7%	14.8%
11	−18.8%	14.2%
12	−22.2%	15.4%
14	−9.9%	8.9%
mean	−12.7%	10.7%
s.d.	4.5%	3.2%