X0202 4 2006-07-27 0 0000109261 ZENITH NATIONAL INSURANCE CORP ZNT 0001014053 TSAI GERALD JR 200 PARK AVENUE, SUITE 4522 NEW YORK NY 10166 1 0 0 0 Common Stock 2006-07-27 4 S 0 2000 40.46 D 73000 I See Footnote Common Stock 2006-07-27 4 S 0 500 39.92 D 72500 I See Footnote Common Stock 2006-07-27 4 S 0 500 40.00 D 72000 I See Footnote Common Stock 2006-07-27 4 S 0 500 40.10 D 71500 I See Footnote Common Stock 2006-07-27 4 S 0 400 40.14 D 71100 I See Footnote Common Stock 2006-07-27 4 S 0 500 40.20 D 70600 I See Footnote Common Stock 2006-07-27 4 S 0 100 40.00 D 70500 I See Footnote Common Stock 2006-07-27 4 S 0 500 40.05 D 70000 I See Footnote Common Stock 2006-07-27 4 S 0 500 40.07 D 69500 I See Footnote Common Stock 2006-07-27 4 S 0 500 40.01 D 69000 I See Footnote Common Stock 2006-07-27 4 S 0 500 40.15 D 68500 I See Footnote Common Stock 2006-07-27 4 S 0 500 40.25 D 68000 I See Footnote Common Stock 2006-07-27 4 S 0 300 40.28 D 67700 I See Footnote Common Stock 2006-07-27 4 S 0 200 40.22 D 67500 I See Footnote Common Stock 2006-07-27 4 S 0 200 40.25 D 67300 I See Footnote Common Stock 2006-07-27 4 S 0 300 40.27 D 67000 I See Footnote Common Stock 2006-07-27 4 S 0 300 40.31 D 66700 I See Footnote Common Stock 2006-07-27 4 S 0 200 40.29 D 66500 I See Footnote Common Stock 2006-07-27 4 S 0 300 40.23 D 66200 I See Footnote Common Stock 2006-07-27 4 S 0 200 40.24 D 66000 I See Footnote Common Stock 2006-07-27 4 S 0 400 40.25 D 65600 I See Footnote Common Stock 2006-07-27 4 S 0 500 40.22 D 65100 I See Footnote Common Stock 2006-07-27 4 S 0 100 40.19 D 65000 I See Footnote Common Stock 2006-07-27 4 S 0 300 39.84 D 64700 I See Footnote Common Stock 2006-07-27 4 S 0 300 39.85 D 64400 I See Footnote Common Stock 2006-07-27 4 S 0 400 39.84 D 64000 I See Footnote Common Stock 2006-07-27 4 S 0 600 39.80 D 63400 I See Footnote Common Stock 2006-07-27 4 S 0 400 39.81 D 63000 I See Footnote Common Stock 30250 D Held in Individual Retirement Account /s/ Gerald Tsai, Jr. 2006-07-28