WORLD RECORD IN THE MEN'S 5,000 METRES (OUTDOORS)
TIME ATHLETE DATE PLACE
14:36.6 Hannes Kolehmainen (FIN) 1912-06-10 Stockholm, Sweden
14:35.4 Paavo Nurmi (FIN) 1922-09-12 Stockholm, Sweden
14:28.2 Paavo Nurmi (FIN) 1924-06-19 Helsinki, Finland
14:17.0 Lauri Lehtinen (FIN) 1932-06-19 Helsinki, Finland
14:08.8 Taisto Mäki (FIN) 1939-06-16 Helsinki, Finland
13:58.2 Gunder Hägg (SWE) 1942-09-20 Gothenburg, Sweden
13:57.2 Emil Zátopek (TCH) 1954-05-30 Paris, France
13:56.6 Vladimir Kuts (URS) 1954-08-29 Berne, Switzerland
13:51.6 Chris Chataway (GBR) 1954-10-13 London, United Kingdom
13:51.2 Vladimir Kuts (URS) 1954-10-23 Prague, Czechoslovakia
13:50.8 Sandor Iharos (HUN) 1955-09-10 Budapest, Hungary
13:46.8 Vladimir Kuts (URS) 1955-09-18 Belgrad, Yugoslavia
13:40.6 Sandor Iharos (HUN) 1955-09-23 Budapest, Hungary
13:36.8 Gordon Pirie (GBR) 1956-06-19 Bergen, Norway
13:35.0 Vladimir Kuts (URS) 1957-10-13 Rome, Italy
13:34.8 Ron Clarke (AUS) 1965-01-16 Hobart, Australia
13:33.6 Ron Clarke (AUS) 1965-02-01 Auckland, New Zealand
13:25.8 Ron Clarke (AUS) 1965-06-04 Compton, USA
13:24.2 Kipchoge Keino (KEN) 1965-11-30 Auckland, New Zealand
13:16.6 Ron Clarke (AUS) 1966-07-05 Stockholm, Sweden
13:16.4 Lasse Virén (FIN) 1972-09-14 Helsinki,Finland
13:13.0 Emiel Puttemans (BEL) 1972-09-20 Brussels, Belgium
13:12.86 Dick Quax (NZL) 1977-07-05 Stockholm, Sweden
13:08.4 Henry Rono (KEN) 1978-04-08 Berkeley, California, USA
13:06.20 Henry Rono (KEN) 1981-09-13 Knarvik, Norway
13:00.41 David Moorcroft (GBR) 1982-07-07 Oslo, Norway
13:00.40 Saïd Aouita (MAR) 1985-07-22 Oslo, Norway
12:58.39 Saïd Aouita (MAR) 1987-07-27 Rome, Italy
12:56.96 Haile Gebrselassie (ETH) 1994-06-04 Hengelo, Netherlands
12:55.30 Moses Kiptanui (KEN) 1995-06-06 Rome, Italy
12:44.39[3] Haile Gebrselassie (ETH) 1995-08-16 Zürich, Switzerland
12:41.86[3] Haile Gebrselassie (ETH) 1997-08-13 Zürich, Switzerland
12:39.74 Daniel Komen (KEN) 1997-08-22 Brussels, Belgium
12:39.36[3] Haile Gebrselassie (ETH) 1998-06-13 Helsinki, Finland
12:37.35 Kenenisa Bekele (ETH) 2004-05-31 Hengelo, Netherlands
looking at the list it appears you get periods when the WR falls quite often then a few years when nothing happens.
1957 - 1965 WR fell from 13.35.0 to 13.34.8
1972 - 1977 WR fell from 13.13.0 to 13.12.86
1982 - 1987 WR fell from 13.00.41 to 12.58.39
1998 - 2004 WR fell from 12.41.86 to 12.37.35