How many times has a player batted over .400 in a single season?

Here's a list of all the players that batted .400 or more. I also included how many at-bats and plate appearences they had that season.

The last time it was done was in 1941 when Ted Williams hit .406.

AVERAGE YEAR AVG AB PA
1 Hugh Duffy 1894 .440 539 616
2 Tip O'Neill 1887 .435 517 572
3 Ross Barnes 1876 .429 322 342
4 Nap Lajoie 1901 .426 544 582
5 Willie Keeler 1897 .424 564 618
6 Rogers Hornsby 1924 .424 536 640
7 George Sisler 1922 .420 586 654
8 Ty Cobb 1911 .420 591 654
9 Fred Dunlap 1884 .412 449 478
10 Ed Delahanty 1899 .410 581 645
11 Jesse Burkett 1896 .410 586 647
12 Jesse Burkett 1895 .409 550 639
13 Ty Cobb 1912 .409 553 609
14 Joe Jackson 1911 .408 571 641
15 Sam Thompson 1894 .407 437 486
16 George Sisler 1920 .407 631 692
17 Ed Delahanty 1894 .407 489 561
18 Ted Williams 1941 .406 456 604
19 Billy Hamilton 1894 .404 544 686
20 Ed Delahanty 1895 .404 480 578
21 Rogers Hornsby 1925 .403 504 605
22 Harry Heilmann 1923 .403 524 626
23 Pete Browning 1887 .402 547 610
24 Rogers Hornsby 1922 .401 623 704
25 Bill Terry 1930 .401 633 710
26 Hughie Jennings 1896 .401 521 602
27 Ty Cobb 1922 .401 526 612