A good start point is the 1986/87 season as this was when automatic promotion to the football league from the Conference was introduced.
CHAMPIONS TABLE SEASON NPL ISTHMIAN SOUTHERN 1986-87 Macclesfield Town Wycombe Wanderers Fisher Athletic 1987-88 Chorley Yeovil Town Aylesbury United 1988–89 Barrow Leytonstone/Ilford Merthyr Tydfil 1989–90 Colne Dynamoes* Sutton United Dover Athletic 1990–91 Witton Albion Redbridge Forest Farnborough Town 1991–92 Stalybridge Celtic Woking Bromsgrove Rovers 1992–93 Southport Chesham Dover Athletic 1993–94 Marine* Stevenage Borough Farnborough Town 1994–95 Marine* Enfield FC* Hednesford Town 1995–96 Bamber Bridge* Hayes Rushden and Diamonds 1996–97 Leek Town Yeovil Town Gresley Rovers* 1997–98 Barrow Kingstonian Forest Green Rovers 1998–99 Altrincham Sutton United Nuneaton Borough 1999-00 Leigh RMI Dag and Red Boston United 2000–01 Stalybridge Celtic Farnborough Town Margate 2001–02 Burton Albion Gravesend and N Kettering Town 2002–03 Accrington Stanley Aldershot Town Tamworth 2003–04 Hucknall Town* Canvey Island Crawley Town ------------ Creation of Conference South and North Divisions ------------ 2004–05 Hyde United Yeading Histon 2005–06 Blyth Spartans Braintree Town Salisbury City 2006–07 Burscough Hampton and Rich Bath City 2007–08 Fleetwood Town Chelmsford City Kings Lynn 2008–09 Eastwood Town Dover Athletic Corby Town 2009–10 Guiseley Dartford Farnborough 2010–11 FC Halifax Town Sutton United Truro City PLAY OFF PROMOTION WINNERS FROM 2004 - 2011 2004-05 Workington Eastleigh Hednesford Town 2005-06 Farsley Celtic Fisher Athletic Bedford Town 2006-07 AFC Telford United Bromley Maidenhead United 2007-08 Gateshead AFC Wimbledon Team Bath 2008-09 Ilkeston Town Staines Town Gloucester City 2009-10 Boston United Boreham Wood Nuneaton Town 2010-11 Colwyn Bay Tonbridge Angels Salisbury City red denotes went to become a football league club * denotes not promoted 1989/90 - Gateshead promoted in place of Colne Dynamoes 1993/94 - No club promoted in place of Marine 1994/95 - Morecambe promoted in place of Marine Slough Town promoted in place of Enfield 1995/96 - No club promoted in place of Bamber Bridge 1996/97 - Cheltenham Town promoted in place of Gresley Rovers 2003/04 - No team promoted in place of Hucknall Town Number of clubs who went into the football league since 1986/87 ISTHMIAN LEAGUE - SIX NORTHERN LEAGUE - FOUR SOUTHERN LEAGUE - FOURAs you can see the since the advent of automatic promotion from the Conference it's the Isthmian League who are winners with a total of six clubs moving up to gain football league status. Both the Southern and Northern League's are on a total of four each although the Southern League counts Boston United and Rushden and Diamonds as the only clubs on the list to be promoted and then relegated from the football league.
The table also shows that since the formation of the Northern and Southern Conference divisions in 2004 it has become harder to gain promotion into the football league with a further division to negotiate. Only AFC Wimbledon have come from the new Step 3 since that time to gain promotion to the football league.
The introduction of two up/two down from League Two in 2002 has also strengthened the Conference league transforming it into a more professional league with a total of fourteen of the twenty-four clubs in the Blue Square Premier for 2011/12 being ex football league sides#.
Going back a decade to 2001/02 the total was just seven of twenty-two club division. This number included Northwich Victoria (members of the league from 1892-1894, Southport (1921 -1974) and Stalybridge Celtic (1921 - 1923).
# - includes the reformed Gateshead and Newport County
Yeovil Town have reached the highest position in the football league when in the 2006/07 season they finished in fifth position in League One and qualified for the Play-Off final at Wembley. The semi-final was was an amazing 5-4 aggregate victory over Nottingham Forest. Although mention must go to Wycombe Wanderers who have gone on to reach the Semi-Final of both the FA Cup and League Cup since joining the league in 1993.
Only Rushden and Diamonds (2002/03) and Yeovil Town (2003/04) have been winners of Division Three/League Two with Wycombe Wanderers, Dagenham & Redbridge, Macclesfield Town, Cheltenham Town and Stevenage Borough all going up via the play-offs or automatic promotion.
WHERE ARE THE CLUBS NOW?? LEAGUE ONE LEAGUE TWO Blue Square North ?????? Stevenage Borough Accrington Stanley Boston United Rushden and Diamonds Wycombe Wanderers AFC Wimbledon Yeovil Town Aldershot Town Burton Albion Cheltenham Town Crawley Town Dag and Red Macclesfield Town MorecambeThe formation of AFC Wimbledon in 2002 and the fantastic story of their rise through the Combined Counties and Isthmian divisions and onto the Blue Square South and National divisions shows the dream of a club climbing up from the depths of the non-league to the football league is still alive.
What Stevenage Borough fan would of thought back in 1990 (they were relegated when finishing second bottom to Wolverton Town in the Isthmian League Division One) that in 2010/11 they would be playing Sheffield Wednesday and Charlton Athletic in the football league?
And what of the next twenty years?? Lowestoft Town v Ipswich Town, Fulham v Sutton United or Gillingham v Chatham Town anyone??