NASD,Total,100.00%,53.46%,34.30%,12.24%
NASD,Automated Trading,72.55%,69.70%,77.21%,71.96%
NASD,Principal,21.35%,26.51%,13.94%,19.58%
NYSE,Total,100.00%,66.28%,24.56%,9.16%
NYSE,Automated Trading,75.39%,71.59%,85.90%,74.75%
NYSE,Principal,21.13%,25.73%,8.76%,21.07%
AMEX,Total,100.00%,69.77%,21.32%,8.91%
AMEX,Automated Trading,91.66%,93.41%,90.72%,80.30%
AMEX,Principal,5.22%,4.52%,6.15%,8.48%