Correct me if I am wrong, but years ago I collected a list of neopronouns by year of coining (only before 2000 otherwise things would get a bit out of hand very quickly). I wanted to share this list with you all!
History of English Neopronouns:
• Ou (1789)
• Ne/Nim/Nis/Nis/Nimself (1850)
• Ve/Vim/Vis/Vis/Vimself (1864)
• Ze (1864)
• Thon/Thon/Thons/Thons/Thonself (1884)
• E/Em/Es/Es/Emself (1890)
• He’er/Him’er/His’er/His’er/Him’erself (1912)
• Hir (1920)
• Ae/Aer/Aer/Aers/Aerself (1920)
• Tey/Tem/Ter/Ters/Temself (1971)
• Xe/Xem/Xyr/Xyrs/Xemself (1973)
• Te/Tir/Tes/Tes/Tirself (1974)
• Ey/Em/Eir/Eirs/Eirself (1975)
• Per/Per/Pers/Pers/Perself (1979)
• Ve/Ver/Vis/Vis/Verself (1980)
• Hu/Hum/Hus/Hus/Humself (1982)
• E/Em/Eir/Eirs/Emself (1983)
• Ze/Hir/Hir/Hirs/Hirself (1996)
• Ze/Mer/Zer/Zers/Zemself (1997)
• Zhe/Zhim/Zher/Zhers/Zhimself (2000)
Sources:
(I am aware that not all of these are the peak of credibility, so please let me know if any of them are incorrect.)