AFAIK having flown these aircraft a long time ago, the EFIS was the standard from the B737-300 (1984) and onwards. Having said that, some jurassic US operators did not want the EFIS (Southwest, United maybe others) and basically got 737-"250s"... With the CFM engine and extended fuselage and the analog instruments.
I have no idea about fleet size with this setup, probably a quite a few if SWA kept getting their -300s this way.
Not sure if any -400 og -500s were delivered with analog instruments.