The correlation between gpm and xpm is 0.94. The more gpm, the more xpm, and vice versa. But some values are higher than expected, some are lower. Efficiency is a difference between the value of xpm depending on gpm (blue dots) with respect to the expected value (red line).
Efficiency
Riki 98.1755
Meepo 59.4939
Nyx Assassin 55.9195
Tinker 45.6489
Anti-Mage 38.3950
Spectre 34.5122
Slark 28.2439
Void Spirit 27.9149
Templar Assassin 27.7822
Io 26.9577
Storm Spirit 26.6325
Troll Warlord 25.6394
Puck 25.4763
Weaver 25.3095
Bane 24.5704
Phantom Assassin 24.2634
Vengeful Spirit 23.6092
Sven 23.2524
Ember Spirit 22.7577
Skywrath Mage 21.9128
Spirit Breaker 21.7794
Ursa 21.5345
Lifestealer 20.5408
Lion 20.1827
Windranger 17.8584
Queen of Pain 17.5576
Bloodseeker 16.3243
Dark Willow 15.6443
Disruptor 15.6114
Clinkz 15.0646
Crystal Maiden 14.9058
Treant Protector 14.6936
Enchantress 14.2870
Juggernaut 14.2652
Faceless Void 14.0774
Tusk 11.9934
Phantom Lancer 11.8665
Magnus 11.4275
Elder Titan 9.3108
Batrider 8.7200
Slardar 8.4495
Pangolier 8.1025
Grimstroke 7.4457
Shadow Fiend 7.0771
Lich 6.3879
Abaddon 6.3832
Earth Spirit 5.9793
Outworld Destroyer 5.4061
Morphling 5.1175
Night Stalker 4.9662
Hoodwink 4.5193
Brewmaster 4.3688
Axe 4.3544
Ancient Apparition 4.0076
Tiny 3.6813
Earthshaker 3.6099
Phoenix 3.2374
Winter Wyvern 3.1743
Legion Commander 3.0521
Bristleback 2.5532
Oracle 1.4875
Death Prophet 0.9372
Chaos Knight 0.8747
Witch Doctor 0.8043
Pudge 0.4439
Necrophos -0.0866
Rubick -0.4482
Sand King -0.6257
Razor -1.1287
Medusa -1.2161
Lina -1.3801
Kunkka -1.8113
Invoker -1.9879
Omniknight -2.1718
Drow Ranger -2.2300
Timbersaw -2.2326
Monkey King -2.2885
Luna -2.6015
Mirana -4.6214
Viper -4.7707
Silencer -5.1739
Huskar -5.2372
Dazzle -5.9307
Visage -5.9465
Jakiro -6.1786
Marci -6.5151
Muerta -6.6801
Shadow Demon -7.5569
Wraith King -7.6512
Tidehunter -7.6694
Zeus -8.2295
Ogre Magi -8.3346
Dragon Knight -9.7010
Primal Beast -9.7917
Gyrocopter -10.7496
Undying -11.8781
Leshrac -13.2138
Broodmother -13.5131
Pugna -14.3152
Dawnbreaker -14.3474
Mars -14.5340
Clockwerk -15.4542
Centaur Warrunner -15.7274
Keeper of the Light -17.3382
Arc Warden -18.1314
Beastmaster -19.3226
Snapfire -20.2130
Techies -20.4672
Sniper -23.9816
Enigma -24.4471
Venomancer -29.1032
Shadow Shaman -29.8719
Dark Seer -31.2112
Underlord -31.4156
Warlock -34.1430
Naga Siren -37.5685
Alchemist -41.8558
Terrorblade -60.7159
Lycan -62.5814
Nature's Prophet -63.2312
Lone Druid -64.7630
Bounty Hunter -68.0733
Chen -70.3424
Doom -77.8257