Taking a look at the source code reveals that "framerate" is actually a float.
Here's the entire thing (not all keyvalues are included here as some entities have their own ones):
typedef struct entvars_s
{
string_t classname;
string_t globalname;
vec3_t origin;
vec3_t oldorigin;
vec3_t velocity;
vec3_t basevelocity;
vec3_t clbasevelocity; // Base velocity that was passed in to server physics so
// client can predict conveyors correctly. Server zeroes it, so we need to store here, too.
vec3_t movedir;
vec3_t angles; // Model angles
vec3_t avelocity; // angle velocity (degrees per second)
vec3_t punchangle; // auto-decaying view angle adjustment
vec3_t v_angle; // Viewing angle (player only)
// For parametric entities
vec3_t endpos;
vec3_t startpos;
float impacttime;
float starttime;
int fixangle; // 0:nothing, 1:force view angles, 2:add avelocity
float idealpitch;
float pitch_speed;
float ideal_yaw;
float yaw_speed;
int modelindex;
string_t model;
int viewmodel; // player's viewmodel
int weaponmodel; // what other players see
vec3_t absmin; // BB max translated to world coord
vec3_t absmax; // BB max translated to world coord
vec3_t mins; // local BB min
vec3_t maxs; // local BB max
vec3_t size; // maxs - mins
float ltime;
float nextthink;
int movetype;
int solid;
int skin;
int body; // sub-model selection for studiomodels
int effects;
float gravity; // % of "normal" gravity
float friction; // inverse elasticity of MOVETYPE_BOUNCE
int light_level;
int sequence; // animation sequence
int gaitsequence; // movement animation sequence for player (0 for none)
float frame; // % playback position in animation sequences (0..255)
float animtime; // world time when frame was set
float framerate; // animation playback rate (-8x to 8x)
byte controller[4]; // bone controller setting (0..255)
byte blending[2]; // blending amount between sub-sequences (0..255)
float scale; // sprite rendering scale (0..255)
int rendermode;
float renderamt;
vec3_t rendercolor;
int renderfx;
float health;
float frags;
int weapons; // bit mask for available weapons
float takedamage;
int deadflag;
vec3_t view_ofs; // eye position
int button;
int impulse;
edict_t *chain; // Entity pointer when linked into a linked list
edict_t *dmg_inflictor;
edict_t *enemy;
edict_t *aiment; // entity pointer when MOVETYPE_FOLLOW
edict_t *owner;
edict_t *groundentity;
int spawnflags;
int flags;
int colormap; // lowbyte topcolor, highbyte bottomcolor
int team;
float max_health;
float teleport_time;
float armortype;
float armorvalue;
int waterlevel;
int watertype;
string_t target;
string_t targetname;
string_t netname;
string_t message;
float dmg_take;
float dmg_save;
float dmg;
float dmgtime;
string_t noise;
string_t noise1;
string_t noise2;
string_t noise3;
float speed;
float air_finished;
float pain_finished;
float radsuit_finished;
edict_t *pContainingEntity;
int playerclass;
float maxspeed;
float fov;
int weaponanim;
int pushmsec;
int bInDuck;
int flTimeStepSound;
int flSwimTime;
int flDuckTime;
int iStepLeft;
float flFallVelocity;
int gamestate;
int oldbuttons;
int groupinfo;
// For mods
int iuser1;
int iuser2;
int iuser3;
int iuser4;
float fuser1;
float fuser2;
float fuser3;
float fuser4;
vec3_t vuser1;
vec3_t vuser2;
vec3_t vuser3;
vec3_t vuser4;
edict_t *euser1;
edict_t *euser2;
edict_t *euser3;
edict_t *euser4;
} entvars_t;
vec3_t -> string
edict_t -> don't list these as keyvalues
string_t -> string
byte -> normally you shouldn't do this, but it'll be an integer
int -> integer
Also, everything after
// For mods
shouldn't be included in FGDs.