Table:
text: List of railway stations in the West Midlands
Stations
Stations
Station Year_opened Metropolitan_borough_c_ Zone_ Servedby_Route_maps_dead_link_dead_link_ Station_users_2006_07 Station_users_2007_08
Acocks Green 1852 Birmingham 3 Chiltern Railways London Midland 160100 161400
Adderley Park 1860 Birmingham 2 London Midland 19500 20400
Aston 1854 Birmingham 2 London Midland 167700 206300
Berkswell 1884 Solihull 5 London Midland 112000 114100
Bescot Stadium 1847 Sandwell 4 London Midland 55000 48200
Birmingham Moor Street 1909 Birmingham 1 Chiltern Railways London Midland 2680800 687400
Birmingham Snow Hill 1852 [d ] Birmingham 1 Chiltern Railways London Midland Midland Metro 1939000 2407300
Blake Street 1884 Birmingham 5 London Midland 175900 184000
Bloxwich 1989 Walsall 5 London Midland 21100 24000
Bloxwich North 1990 Walsall 5 London Midland 23800 26600

text: List of railway stations in the West Midlands
Stations
Stations
Station Year_opened Metropolitan_borough_c_ Zone_ Servedby_Route_maps_dead_link_dead_link_ Station_users_2006_07 Station_users_2007_08
Bordesley 1855 Birmingham 2 London Midland 3700 4000
Bournville 1876 Birmingham 3 London Midland 405900 466900
Butlers Lane 1957 Birmingham 5 London Midland 96000 103000
Canley 1940 Coventry 5 London Midland 77900 90000
Chester Road 1863 Birmingham 3 London Midland 266700 296200
Coseley 1852 [e ] Dudley 5 London Midland 117200 126600
Coventry 1838 Coventry 5 CrossCountry London Midland Virgin Trains 2874900 3039500
Cradley Heath 1863 Sandwell 5 Chiltern Railways London Midland 242500 288300
Dorridge 1852 Solihull 5 Chiltern Railways London Midland 300800 304500
Duddeston 1837 Birmingham 2 London Midland 55700 59900
Dudley Port 1852 [f ] Sandwell 4 London Midland 144300 155200

text: List of railway stations in the West Midlands
Stations
Stations
Station Year_opened Metropolitan_borough_c_ Zone_ Servedby_Route_maps_dead_link_dead_link_ Station_users_2006_07 Station_users_2007_08
Earlswood [a ] 1908 Solihull 5 London Midland 38400 32400
Erdington 1862 Birmingham 3 London Midland 299100 336000
Five Ways 1885 [g ] Birmingham 1 London Midland 514400 563900
Four Oaks 1884 Birmingham 5 London Midland 251000 276600
Gravelly Hill 1862 Birmingham 2 London Midland 199900 231400
Hall Green 1908 Birmingham 3 London Midland 143500 139400
Hampton-in-Arden 1837 [h ] Solihull 5 London Midland 54900 57300
Hamstead 1862 Birmingham 3 London Midland 67100 69500
Jewellery Quarter 1995 Birmingham 1 Chiltern Railways London Midland Midland Metro 108700 116800
Kings Norton 1849 Birmingham 3 London Midland 447500 481400
Langley Green 1885 Sandwell 3 Chiltern Railways London Midland 57900 60900

text: List of railway stations in the West Midlands
Stations
Stations
Station Year_opened Metropolitan_borough_c_ Zone_ Servedby_Route_maps_dead_link_dead_link_ Station_users_2006_07 Station_users_2007_08
Lea Hall 1939 Birmingham 3 London Midland 146800 141200
Longbridge 1978 [i ] Birmingham 4 London Midland 342800 373300
Lye 1863 Dudley 5 Chiltern Railways London Midland 40400 46400
Marston Green 1844 Solihull 4 London Midland 183000 182200
Northfield 1870 Birmingham 4 London Midland 305800 333100
Old Hill 1866 Sandwell 4 Chiltern Railways London Midland 79000 83100
Olton 1869 Solihull 4 Chiltern Railways London Midland 140200 143100
Perry Barr 1837 Birmingham 2 London Midland 164100 172600
Rowley Regis 1867 Sandwell 3 Chiltern Railways London Midland 295900 325000
Sandwell and Dudley 1852 Sandwell 4 London Midland Virgin Trains 280000 314600
Selly Oak 1876 Birmingham 2 London Midland 1023500 1113300

text: List of railway stations in the West Midlands
Stations
Stations
Station Year_opened Metropolitan_borough_c_ Zone_ Servedby_Route_maps_dead_link_dead_link_ Station_users_2006_07 Station_users_2007_08
Shirley 1908 Solihull 4 London Midland 172700 164000
Small Heath 1863 Birmingham 2 Chiltern Railways London Midland 37200 37700
Smethwick Rolfe Street 1852 Sandwell 2 London Midland 113600 107100
Solihull 1852 Solihull 4 Chiltern Railways London Midland 651800 662700
Spring Road 1908 Birmingham 3 London Midland 82800 77000
Stechford 1844 Birmingham 3 London Midland 109200 119800
Stourbridge Junction 1852 Dudley 5 Chiltern Railways London Midland 444200 499600
Stourbridge Town 1879 [j ] Dudley 5 London Midland 258700 278800
Sutton Coldfield 1862 [k ] Birmingham 4 London Midland 578100 634300
Tame Bridge Parkway 1990 Sandwell 4 London Midland Wrexham & Shropshire | 177800 189700

text: List of railway stations in the West Midlands
Stations
Stations
Station Year_opened Metropolitan_borough_c_ Zone_ Servedby_Route_maps_dead_link_dead_link_ Station_users_2006_07 Station_users_2007_08
The Hawthorns 1931 [l ] Sandwell 2 Chiltern Railways London Midland Midland Metro 145700 157200
Tile Hill 1864 Coventry 5 London Midland 130700 142100
Tipton 1852 Sandwell 5 London Midland 124600 126800
Tyseley 1906 Birmingham 2 Chiltern Railways London Midland 63200 66500
University 1978 Birmingham 2 CrossCountry London Midland 1190800 1250900
Walsall 1849 [m ] Walsall 4 London Midland 583300 587000
Whitlocks End 1936 Solihull 4 London Midland 23500 26600
Widney Manor 1899 Solihull 4 Chiltern Railways London Midland 119500 116900
Witton 1876 Birmingham 2 London Midland 77400 99800
Wylde Green 1862 Birmingham 4 London Midland 223900 243800
Wythall [a ] 1908 Bromsgrove 5 London Midland 31400 30300

Question: What is the largest zone under the list of West Midlands train stations?