Help with Some History

[Corsulian]

I've been doing a lot of work on our Wikipedia pages as they're probably the first place anyone looks for information. I'm planning to do a fancy time-lapse animation of all our chapters from 1873-2008. To make it work, however, I need some help with a few closing/re-chartering dates that are missing:

Psi 1907-1916, 1921-1936, ?-Present
Alpha Epsilon 1910-?, 1994-2007
Zeta Deuteron 1917-1929, ?-1973
Eta Deuteron 1917-?
Upsilon Deuteron 1926-1936, ?-1982
Epsilon Delta 1930-?
Epsilon Zeta 1930-?
Epsilon Eta 1931-?
Epsilon Theta 1935-?
Chi Triton 1949-?, 2008-Present
Epsilon Upsilon 1950-?
Delta Tetarton 1950-?, 1993-Present
Epsilon Tetarton 1952-?
Epsilon Chi 1952-?
Phi Delta 1955-?
Phi Gamma 1956-?
Phi Epsilon 1956-?
Phi Lambda 1956-?
Kappa Tetarton 1957-?, 2003-Present
Phi Zeta 1958-?
Phi Eta 1959-?
Phi Theta 1958-?
Sigma Chi 1960-?
Phi Pi 1960-?
Sigma Tetarton 1960-?, 2002-Present
Sigma Alpha 1960-?
Phi Omicron 1961-?
Phi Nu 1962-?
Phi Xi 1962-?
Beta Pentaton 1963-?, 2003-Present
Gamma Pentaton 1963-?
Phi Rho 1963-?
Zeta Pentaton 1964-?
Phi Sigma 1965-?
Phi Phi 1965-?
Kappa Pentaton 1966-?, 2004-Present
Xi Pentaton 1967-1970, ?-Present
Sigma Beta 1967-?
Sigma Delta 1968-?
Phi Pentaton 1968-?
Sigma Epsilon 1968-?
Sigma Gamma 1969-?
Sigma Eta 1969-?
Sigma Kappa 1969-?
Sigma Iota 1969-?
Psi Pentaton 1969-?
Sigma Theta 1969-?
Sigma Lambda 1969-?
Sigma Mu 1969-?
Sigma Nu 1970-?
Phi Omega 1970-?
Sigma Xi 1970-?
Phi Chi 1970-?
Phi Psi 1970-?
Beta Hexaton 1971-?
Epsilon Hexaton 1972-?, 2007-Present
Eta Hexaton 1972-?, 2001-Present
Iota Hexaton 1973-?
Lambda Hexaton 1976-?
Mu Hexaton 1976-?, 2007-Present
Xi Hexaton 1976-?
Pi Hexaton 1979-?
Chi Hexaton 1988-?
Psi Hexaton 1989-?
Omega Hexaton 1989-?
Delta Septaton 1990-?
Zeta Septaton 1990-?
Theta Septaton 1992-?
Pi Septaton 1996-?
Rho Septaton 1999-?