Here are the top 50 best performing songs and their normalised scores, if we look separately at the Gaon annual top 100 for both streams and downloads, pre-2018:
STREAMING
01: Cherry Blossom Ending – Busker Busker [516.96%]
02: Wild Flower – Park Hyo-shin [386.54%]
03: No Matter Where – M.C The Max [303.52%]
04: Cheer Up – Twice [298.39%]
05: Friday (Feat. Jang Yi-jeong) – IU [294.36%]
06: Galaxy – Bolbbalgan4 [284.95%]
07: Some (Feat. Lil Boi of Geeks) – Soyou, Junggigo [281.87%]
08: Love Again – Im Chang-jung [280.49%]
09: Memory of the Wind – Naul [270.06%]
10: A Midsummer Night's Sweetness – San E, Raina [264.42%]
11: I Don't Love You – Urban Zakapa [260.21%]
12: Making a New Ending for This Story – Han Dong-geun [257.80%]
13: The Meaning of You (Feat. Kim Chang-wan) – IU [253.58%]
14: I Will Go to You Like the First Snow – Ailee [249.51%]
15: Me Gustas Tu – GFriend [243.73%]
16: Growl – EXO [235.98%]
17: Not Spring, Love, or Cherry Blossoms – High4, IU [235.28%]
18: Lost Stars – Adam Levine [233.38%]
19: Johnny (Feat. Dynamicduo) – Primary [233.25%]
20: D (Half Moon) (Feat. Gaeko) – Dean [233.19%]
21: TT – Twice [231.30%]
22: Don't Come Back (Feat. Yong Jun-hyung of Beast) – Heize [227.06%]
23: The Love I Committed – Im Chang-jung, [224.06%]
24: I'm Not the Only One – Sam Smith [223.53%]
25: Officially Missing You, Too – Geeks, Soyou [223.36%]
26: ? (Question Mark) (Feat. Choiza, Zion.T) – Primary [217.58%]
27: Hard to Love – Bolbbalgan4 [217.09%]
28: Stupid in Love – Soyou, Mad Clown [214.75%]
29: Gangnam Style – Psy [214.50%]
30: Amazing You – Han Dong-geun [211.85%]
31: Rough – GFriend [201.11%]
32: Bad Girl Good Girl – Miss A [199.50%]
33: If It Is You – Jung Seung-hwan [198.14%]
34: Boys and Girls (Feat. Babylon) – Zico [195.92%]
35: Good Day – IU [195.67%]
36: Through the Night – IU [195.33%]
37: Playing with Fire – Blackpink [195.17%]
38: Heartsore Story (Feat. Yong Jun-hyung) – Wheesung [195.06%]
39: Eyes, Nose, Lips – Taeyang [191.98%]
40: You & I – IU [191.76%]
41: Like It – Yoon Jong-shin [191.26%]
42: I Can't Go to Shinchon – Postmen [190.99%]
43: Tell Me You Love Me – Bolbbalgan4 [184.77%]
44: I Miss You – Noel [184.45%]
45: Can't Let You Go Even If I Die – 2AM [182.67%]
46: Maps – Maroon 5 [181.95%]
47: A Little Girl – Oh Hyuk [180.85%]
48: Bang Bang Bang – Big Bang [180.81%]
49: You in the Same Time – Naul [180.68%]
50: Alone – Sistar [179.91%]
DOWNLOAD
01: Cherry Blossom Ending – Busker Busker [495.36%]
02: Wild Flower – Park Hyo-shin [356.38%]
03: I'm Not the Only One – Sam Smith [280.43%]
04: Cheer Up – Twice [265.17%]
05: No Matter Where – M.C The Max [263.99%]
06: The Meaning of You (Feat. Kim Chang-wan) – IU [258.91%]
07: Love Again – Im Chang-jung [258.55%]
08: Galaxy – Bolbbalgan4 [253.91%]
09: I Don't Love You – Urban Zakapa [251.88%]
10: Friday (Feat. Jang Yi-jeong) – IU [247.79%]
11: You & I – IU [238.68%]
12: Some (Feat. Lil Boi of Geeks) – Soyou, Junggigo [235.66%]
13: A Midsummer Night's Sweetness – San E, Raina [231.06%]
14: Making a New Ending for This Story – Han Dong-geun [226.45%]
15: Me Gustas Tu – GFriend [224.14%]
16: Don't Worry – Lee Juck [220.51%]
17: D (Half Moon) (Feat. Gaeko) – Dean [219.44%]
18: I Will Go to You Like the First Snow – Ailee [214.78%]
19: Lost Stars – Adam Levine [212.09%]
20: The Love I Committed – Im Chang-jung, [208.79%]
21: Hard to Love – Bolbbalgan4 [205.79%]
22: Trouble Maker – Trouble Maker [203.87%]
23: Don't Come Back (Feat. Yong Jun-hyung of Beast) – Heize [203.14%]
24: TT – Twice [202.95%]
25: Moves Like Jagger (Feat. Christina Aguilera) – Maroon 5 [202.34%]
26: Rough – GFriend [194.20%]
27: If It Is You – Jung Seung-hwan [193.65%]
28: Love Yourself – Justin Bieber [193.13%]
29: I (Feat. Verbal Jint) – Taeyeon [189.41%]
30: Memory of the Wind – Naul [188.59%]
31: Through the Night – IU [188.29%]
32: Gangnam Style – Psy [185.96%]
33: A Little Girl – Oh Hyuk [185.94%]
34: Amazing You – Han Dong-geun [185.34%]
35: Let It Go – Idina Menzel [184.99%]
36: Boys and Girls (Feat. Babylon) – Zico [184.64%]
37: Lovey-Dovey – T-ara [181.93%]
38: Playing with Fire – Blackpink [181.28%]
39: Shower of Tears (Feat. Ailee) – Baechigi [180.22%]
40: Roly-Poly – T-ara [179.20%]
41: Officially Missing You, Too – Geeks, Soyou [173.94%]
42: Tears (Feat. Eugene) – Leessang [173.09%]
43: Eyes, Nose, Lips – Taeyang [171.79%]
44: This Love – Davichi [170.53%]
45: Twenty-Three – IU [169.23%]
46: Can't Let You Go Even If I Die – 2AM [168.65%]
47: Russian Roulette – Red Velvet [167.62%]
48: Shape of You – Ed Sheeran [167.16%]
49: Oh! – Girls' Generation [166.84%]
50: Bang Bang Bang – Big Bang [166.53%]